Adapt code blocks to what they actually are

README.md

@@ -33,7 +33,7 @@ working in very large code bases
 
 To use `elvis` as a standalone tool, you need to:
 
-```bash
+```console
 git clone https://github.com/inaka/elvis
 cd elvis
 rebar3 escriptize
@@ -147,7 +147,7 @@ For example, if the rule is in one of your dependencies, you can run `elvis rock
 `elvis` can be used as a [`git` pre-commit hook](https://git-scm.com/book/en/Customizing-Git-Git-Hooks#Client-Side-Hooks)
 using the `git-hook` command (installable via `install git-hook`) as:
 
-```bash
+```sh
 #!/bin/sh
 elvis git-hook
 ```