Improve search discoverability of the docs and Pages site

README leads with the logo (keyworded alt text), PROFILES.md titles
itself by what it offers (NVIDIA overclock & undervolt profiles), and
the Pages config gains canonical url/baseurl, a tagline that becomes
the homepage title suffix, a sitemap, and the icon as JSON-LD logo and
default og:image.

assets/render_social_preview.py renders the GitHub social preview card
(1280x640) in the icon's visual language, reusing render_icon.py's
palette and drawing helpers; the card must be uploaded manually in
repo Settings, as GitHub has no API for it.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0127xi8PYUSabiLV6YUD29Cb

Author: vuplea

.gitignore

@@ -9,3 +9,6 @@ profiles/out/
 .idea/
 *.user
 *.suo
+
+# Python (assets render scripts)
+__pycache__/

PROFILES.md

@@ -1,4 +1,4 @@
-# Ready-made tuning profiles
+# Ready-made NVIDIA overclock & undervolt profiles
 
 Folders of profile shortcuts per card range are offered. They are based on instrumented reviews
 and large owner discussion threads, cited inline below.

README.md

@@ -1,3 +1,5 @@
+<img src="assets/icon.png" alt="simple-nvidia-undervolt logo: an NVIDIA GPU voltage/frequency curve flattening at the voltage cap" width="96" align="right">
+
 # simple-nvidia-undervolt
 
 A small Windows command-line alternative to MSI Afterburner for overclocking or undervolting an NVIDIA GPU.

_config.yml

@@ -1,8 +1,19 @@
 title: simple-nvidia-undervolt
+tagline: Overclock & undervolt NVIDIA GPUs from the Windows command line
 description: >-
-  Command-line NVIDIA GPU undervolting for Windows — a lightweight MSI
-  Afterburner alternative. Caps voltage by flattening the V/F curve,
-  no background process. Tested on RTX 5090 (Blackwell).
+  Overclock or undervolt your NVIDIA GPU from the Windows command line — a
+  lightweight MSI Afterburner alternative. Caps voltage by flattening the
+  V/F curve, no background process. Tested on RTX 5090 (Blackwell).
+url: https://vuplea.github.io
+baseurl: /simple-nvidia-undervolt
+lang: en
+logo: /assets/icon.png
 theme: jekyll-theme-slate
 plugins:
   - jekyll-seo-tag
+  - jekyll-sitemap
+defaults:
+  - scope:
+      path: ""
+    values:
+      image: /assets/icon.png

assets/render_social_preview.py

@@ -0,0 +1,117 @@
+"""
+Generates the GitHub social preview card (social-preview.png, 1280x640) in the
+icon's visual language: the V/F curve rising and hard-flattening at the voltage
+cap, glowing over pinstripes, with the project name and tagline set below.
+
+Upload manually: repo Settings -> Social preview (GitHub has no API for it).
+
+Requires Python 3 with numpy and pillow:  python render_social_preview.py
+"""
+
+import os
+
+import numpy as np
+from PIL import Image, ImageDraw, ImageFilter, ImageFont
+
+from render_icon import GREEN, HOT, INK, MINT, NEARBLK, over, sd_polyline, smoothstep
+
+OUT_DIR = os.path.dirname(os.path.abspath(__file__))
+W, H = 1280, 640
+SS = 2
+NX, NY = W * SS, H * SS
+
+TITLE = "simple-nvidia-undervolt"
+TAGLINE = "Overclock & undervolt NVIDIA GPUs from the Windows command line"
+
+# V/F curve in card coordinates (x in [-2, 2], y in [-1, 1], y up):
+# rise starts at (X0, Y0), hard-flattens at the knee (XK, YC)
+X0, XK = -1.85, -0.45
+Y0, YC = -0.30, 0.42
+
+
+def curve_y(x):
+    t = np.clip((x - X0) / (XK - X0), 0.0, 1.0)
+    return Y0 + (YC - Y0) * t ** 1.6
+
+
+def render_background():
+    xs = np.linspace(-2.0, 2.0, NX)
+    ys = np.linspace(1.0, -1.0, NY)
+    x, y = np.meshgrid(xs, ys)
+
+    # dark ground with a slight radial falloff
+    r = np.hypot(x * 0.5, y)
+    col = INK[None, None, :] * (1.0 - 0.35 * smoothstep(0.2, 1.4, r))[..., None]
+    col = col + NEARBLK[None, None, :] * 0.5
+
+    fy = curve_y(x)
+    dyc = y - fy
+    below = smoothstep(0.015, -0.015, dyc)
+
+    # faint fill so the stripes sit in a body of tone, not a void
+    col = col + GREEN[None, None, :] * (below * np.exp(dyc * 1.6) * 0.18)[..., None]
+
+    # pinstripes that relax toward horizontal with depth
+    offsets = [0.16, 0.35, 0.56, 0.80, 1.06]
+    for i, off in enumerate(offsets):
+        relax = (i + 1) / (len(offsets) + 1)
+        shape = fy * (1 - relax) + YC * relax
+        swell = 0.028 * np.sin(x * 1.8 + i * 1.4) * relax
+        sd = np.abs(y - (shape - off) + swell)
+        alpha = 0.45 * (0.80 ** i)
+        line = smoothstep(0.016, 0.004, sd) * below
+        col = over(col, (GREEN * (0.9 - 0.09 * i))[None, None, :], line * alpha)
+
+    # the curve itself: broad green bloom, lime glow, white-hot core
+    cx = np.linspace(-2.2, 2.2, 140)
+    d = sd_polyline(x, y, list(zip(cx, curve_y(cx))))
+    col = col + GREEN[None, None, :] * np.exp(-7.0 * d)[..., None] * 0.60
+    col = col + MINT[None, None, :] * np.exp(-24.0 * d)[..., None] * 0.80
+    col = over(col, HOT[None, None, :], smoothstep(0.022, 0.007, d))
+
+    # finish: vignette, subtle scanlines and grain, filmic tone curve
+    col = col * (1.0 - 0.45 * smoothstep(0.45, 1.25, r))[..., None]
+    col = col * (1.0 - 0.03 * (0.5 + 0.5 * np.sin(y * NY * 90.0)))[..., None]
+    rng = np.random.default_rng(7)
+    col = col * (1.0 + 0.012 * (rng.random((NY, NX)) - 0.5) * 2.0)[..., None]
+    col = col / (col + 0.85) * 1.85
+
+    col = np.clip(col, 0, 1).reshape(H, SS, W, SS, 3).mean(axis=(1, 3))
+    return Image.fromarray((col * 255 + 0.5).astype(np.uint8))
+
+
+def font(path, size):
+    return ImageFont.truetype(os.path.join(os.environ["WINDIR"], "Fonts", path), size)
+
+
+def main():
+    img = render_background()
+
+    title_font = font("consolab.ttf", 74)
+    tag_font = font("segoeui.ttf", 34)
+
+    halo = Image.new("L", img.size, 0)
+    hd = ImageDraw.Draw(halo)
+    d = ImageDraw.Draw(img)
+
+    for cy, text, f in [(408, TITLE, title_font), (516, TAGLINE, tag_font)]:
+        w = hd.textlength(text, font=f)
+        hd.text(((W - w) / 2, cy), text, font=f, fill=255)
+    halo = halo.filter(ImageFilter.GaussianBlur(24))
+    img.paste(Image.new("RGB", img.size, (4, 7, 6)), (0, 0),
+              halo.point(lambda a: min(int(a * 1.7), 215)))
+
+    for cy, text, f, fill in [
+        (408, TITLE, title_font, (222, 255, 236)),
+        (516, TAGLINE, tag_font, (148, 196, 168)),
+    ]:
+        w = d.textlength(text, font=f)
+        d.text(((W - w) / 2, cy), text, font=f, fill=fill)
+
+    out = os.path.join(OUT_DIR, "social-preview.png")
+    img.save(out)
+    print(f"wrote {out}")
+
+
+if __name__ == "__main__":
+    main()