Improve documentation for git line endings

This has been raised in the slack channel a number of times, and the [proposed solution in the documentation](https://docs.conan.io/2/knowledge/faq.html#error-obtaining-different-revisions-in-linux-and-windows) hasn't worked for me in the past (not saying it doesn't work at all, just didn't in my circumstance). It might be worth expanding this to include a `.gitattributes` solution, in which a `.gitattributes` file is placed in the root of the repository with the following:

```
* text=auto eol=lf
*.bat eol=crlf
*.cmd eol=crlf
*.ps1 eol=crlf
```

Then, to apply these changes to a repository that's already been checked out and/or fix the line endings in the index:

```bash
git rm --cached -r .
git reset --hard
git add --renormalize .
git commit
```

For a reasonably comprehensive discussion of the issues, see [this slack conversation](https://cpplang.slack.com/archives/C41CWV9HA/p1682685524809969?thread_ts=1682676599.267299&cid=C41CWV9HA)