Fix some comments

Signed-off-by: JohnEndson <jiayuzhen@outlook.com>

Author: JohnEndson

src/borrow_check/opaque-types-region-inference-restrictions.md

@@ -19,7 +19,7 @@ Example of case (1):
 ```rust
 type Opaque<X> = impl Sized;
 
-// `T` is a type paramter.
+// `T` is a type parameter.
 // Opaque<T> := ();
 fn good<T>() -> Opaque<T> {}
 
@@ -42,7 +42,7 @@ fn bad<T>(t: T) -> Opaque<T, T> { t } //~ ERROR
 ```
 **Motivation:** In the first case `Opaque<()> := ()`, the hidden type is ambiguous because
 it is compatible with two different interpretaions: `Opaque<X> := X` and `Opaque<X> := ()`.
-Similarily for the second case `Opaque<T, T> := T`, it is ambiguous whether it should be
+Similarly for the second case `Opaque<T, T> := T`, it is ambiguous whether it should be
 interpreted as `Opaque<X, Y> := X` or as `Opaque<X, Y> := Y`.
 Because of this ambiguity, both cases are rejected as invalid defining uses.
 

src/building/suggested.md

@@ -303,7 +303,7 @@ let
   ''
 pkgs.mkShell {
   /* ... */
-  # This environment varaible tells bootstrap where our config.toml is.
+  # This environment variable tells bootstrap where our config.toml is.
   RUST_BOOTSTRAP_CONFIG = config;
 }
 ```

src/git.md

@@ -170,7 +170,7 @@ error: Please commit or stash them.
 (See <https://git-scm.com/book/en/v2/Getting-Started-What-is-Git%3F#_the_three_states> for the difference between the two.)
 
 This means you have made changes since the last time you made a commit. To be able to rebase, either
-commit your changes, or make a temporary commit called a "stash" to have them still not be commited
+commit your changes, or make a temporary commit called a "stash" to have them still not be committed
 when you finish rebasing. You may want to configure git to make this "stash" automatically, which
 will prevent the "cannot rebase" error in nearly all cases:
 

src/solve/invariants.md

@@ -8,7 +8,7 @@ a few of them do not hold in Rust right now. This is either a fundamental to its
 caused by bugs and something that may change in the future.
 
 It is important to know about the things you can assume while working on - and with - the
-type system, so here's an incomplete and inofficial list of invariants of
+type system, so here's an incomplete and unofficial list of invariants of
 the core type system:
 
 - ✅: this invariant mostly holds, with some weird exceptions, you can rely on it outside

src/what-does-early-late-bound-mean.md

@@ -73,7 +73,7 @@ closure type. Closures are [currently unsound](https://github.com/rust-lang/rust
 ways that are closely related to the distinction between early/late bound
 parameters (more on this later)
 
-The early/late boundness of generic parameters is only relevent for the desugaring of
+The early/late boundness of generic parameters is only relevant for the desugaring of
 functions/closures into types with builtin `Fn*` impls. It does not make sense to talk about
 in other contexts.