Auto merge of #13261 - antonilol:fix-doc-code-blocks, r=xFrednet

fix code blocks in doc comments inconsistently using 3 or 4 spaces of indentation

The metadata collector script was treating the space lines all start with as indentation. This caused code block's triple backticks to get a space in front of it, like this:
```
 ```rust
^ this space
```
Code after that that is indented with 4 spaces will only have 3 of those rendered.
Example (taken from [here](https://rust-lang.github.io/rust-clippy/master/index.html#/missing_panics_doc)):
```rust
...
pub fn divide_by(x: i32, y: i32) -> i32 {
   if y == 0 {                      // 3 spaces
       panic!("Cannot divide by 0") // 7 spaces
...
```

Also added 'compile_fail' alongside the other rustdoc directives (second code block [here](https://rust-lang.github.io/rust-clippy/master/index.html#/macro_metavars_in_unsafe) had no highlighting), fixed a doc comment using 'rs' instead of 'rust' and removed some spaces causing an extra missing space of indentation (see second code block [here](https://rust-lang.github.io/rust-clippy/master/index.html#/map_err_ignore)).

changelog: none

1 files changed, 3 insertions, 3 deletions

diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs
index 1d7b10fe8f0..d7126990edb 100644
--- a/clippy_lints/src/methods/mod.rs
+++ b/clippy_lints/src/methods/mod.rs
@@ -2702,10 +2702,10 @@ declare_clippy_lint! {
     ///             }
     ///         })
     /// }
-    ///  ```
+    /// ```
     ///
-    ///  After:
-    ///  ```rust
+    /// After:
+    /// ```rust
     /// use std::{fmt, num::ParseIntError};
     ///
     /// #[derive(Debug)]