fixed typos, added typos checking to CI

compiler/builtins/docs/List.roc

@@ -180,7 +180,7 @@ interface List2
 ## we can free it immediately because there are no other refcounts. However,
 ## in the case of `lists`, we have to iterate through the list and decrement
 ## the refcounts of each of its contained lists - because they, too, have
-## refcounts! Importantly, beacuse the first element had its refcount incremented
+## refcounts! Importantly, because the first element had its refcount incremented
 ## because the function returned `first`, that element will actually end up
 ## *not* getting freed at the end - but all the others will be.
 ##

compiler/builtins/docs/Num.roc

@@ -318,7 +318,7 @@ Int size : Num [ @Int size ]
 ## >>> coordinates.x + 1
 ##
 ## On the last line, the compiler infers that the `1` in `+ 1` is an #F32
-## beacuse it's being added to `coordinates.x`, which was defined to be an #F32
+## because it's being added to `coordinates.x`, which was defined to be an #F32
 ## on the first line.
 ##
 ## Sometimes the compiler has no information about which specific type to pick.
@@ -621,7 +621,7 @@ trunc : Float * -> Int *
 ## Since #Nat has a different maximum number depending on the system you're building
 ## for, this may give a different answer on different systems.
 ##
-## For example, on a 32-bit sytem, #Num.maxNat will return the same answer as
+## For example, on a 32-bit system, #Num.maxNat will return the same answer as
 ## #Num.maxU32. This means that calling `Num.toNat 9_000_000_000` on a 32-bit
 ## system will return #Num.maxU32 instead of 9 billion, because 9 billion is
 ## higher than #Num.maxU32 and will not fit in a #Nat on a 32-bit system.

compiler/builtins/docs/Str.roc

@@ -194,7 +194,7 @@ startsWith : Str, Str -> Bool
 ## if you want to check whether a string begins with something that's representable
 ## in a single code point, you can use (for example) `Str.startsWithCodePoint '鹏'`
 ## instead of `Str.startsWithCodePoint "鹏"`. ('鹏' evaluates to the [U32]
-## value `40527`.) This will not work for graphemes which take up mulitple code
+## value `40527`.) This will not work for graphemes which take up multiple code
 ## points, however; `Str.startsWithCodePoint '👩‍👩‍👦‍👦'` would be a compiler error
 ## because 👩‍👩‍👦‍👦 takes up multiple code points and cannot be represented as a
 ## single [U32]. You'd need to use `Str.startsWithCodePoint "🕊"` instead.