Incorrect indented code formatting

Having code block indented with 4 spaces (like in a list) renders incorrectly:

_https://docs.fastlane.tools/getting-started/ios/screenshots/#setting-up-snapshot_

The issue is caused by `Python-Markdown` and was reported here: https://github.com/Python-Markdown/markdown/issues/53, which is on the [roadmap for 3.0](https://github.com/Python-Markdown/markdown/wiki/3.0-Roadmap).

We can either wait for it to be fixed, then released, then a release from `mkdocs` including it, or we can remove the indentation and change the next list element to `12.` instead of `1.`.