Fix the documentation so that it looks sane in Vim too (#1437)

Author: nedtwigg

CONTRIBUTING.md

@@ -36,7 +36,7 @@ For the folders below in monospace text, they are published on maven central at
 | `lib-extra` | Contains the optional parts of Spotless which require external dependencies.  `LineEnding.GIT_ATTRIBUTES` won't work unless `lib-extra` is available. |
 | `plugin-gradle` | Integrates spotless and all of its formatters into Gradle. |
 | `plugin-maven` | Integrates spotless and all of its formatters into Maven. |
-| _ext | Folder for generating glue jars (specifically packaging Eclipse jars from p2 for consumption using maven).
+| `_ext` | Folder for generating glue jars (specifically packaging Eclipse jars from p2 for consumption using maven).
 
 ## How to add a new FormatterStep
 
@@ -119,7 +119,7 @@ There are many great formatters (prettier, clang-format, black, etc.) which live
 
 Because of Spotless' up-to-date checking and [git ratcheting](https://github.com/diffplug/spotless/tree/main/plugin-gradle#ratchet), Spotless actually doesn't have to call formatters very often, so even an expensive shell call for every single invocation isn't that bad.  Anything that works is better than nothing, and we can always speed things up later if it feels too slow (but it probably won't).
 
-## How to enable the _ext projects
+## How to enable the `_ext` projects
 
 The `_ext` projects are disabled per default, since: