Fix small typo in introduction.md & about.md (#2858)

[no important files changed]

Author: resu-xuniL

concepts/type-checking/about.md

@@ -74,7 +74,7 @@ The `Array` class has a method called `Array.isArray()` that checks if its argum
 
 While `instanceof Array` will not work with an array created in a different realm such as an `iframe` in a webpage, `Array.isArray()` will.
 
-This is because the Array class has a different constructor in each realm, and each `iframe` has its own ream, meaning that the function in the prototype chain will be different, causing `instanceof Array` to fail.
+This is because the Array class has a different constructor in each realm, and each `iframe` has its own realm, meaning that the function in the prototype chain will be different, causing `instanceof Array` to fail.
 `Array.isArray()` is capable of ignoring this, and should always be used when possible.
 
 It can also survive false positives where an object isn't actually an `Array`, and merely has `Array` in its prototype chain.

concepts/type-checking/introduction.md

@@ -74,7 +74,7 @@ The `Array` class has a method called `Array.isArray()` that checks if its argum
 
 While `instanceof Array` will not work with an array created in a different realm such as an `iframe` in a webpage, `Array.isArray()` will.
 
-This is because the Array class has a different constructor in each realm, and each `iframe` has its own ream, meaning that the function in the prototype chain will be different, causing `instanceof Array` to fail.
+This is because the Array class has a different constructor in each realm, and each `iframe` has its own realm, meaning that the function in the prototype chain will be different, causing `instanceof Array` to fail.
 `Array.isArray()` is capable of ignoring this, and should always be used when possible.
 
 It can also survive false positives where an object isn't actually an `Array`, and merely has `Array` in its prototype chain.

exercises/concept/recycling-robot/.docs/introduction.md

@@ -74,7 +74,7 @@ The `Array` class has a method called `Array.isArray()` that checks if its argum
 
 While `instanceof Array` will not work with an array created in a different realm such as an `iframe` in a webpage, `Array.isArray()` will.
 
-This is because the Array class has a different constructor in each realm, and each `iframe` has its own ream, meaning that the function in the prototype chain will be different, causing `instanceof Array` to fail.
+This is because the Array class has a different constructor in each realm, and each `iframe` has its own realm, meaning that the function in the prototype chain will be different, causing `instanceof Array` to fail.
 `Array.isArray()` is capable of ignoring this, and should always be used when possible.
 
 It can also survive false positives where an object isn't actually an `Array`, and merely has `Array` in its prototype chain.