bevy-website repo: Setup instructions including linters/formatters which should be used.

[laundmo]

Its possible to figure some of the linters/tools that are used by looking at the various dot-files in this repo, but it would be very useful to have that mentioned in the readme or contributing/developing guide.

Case in point: I only noticed mega-linter after one of my PRs failed CI.

[TrialDragon]

The linters that can be run by the user are mentioned in the contributing guides writing docs page at the technical section: https://bevy.org/learn/contribute/helping-out/writing-docs/

MegaLinter wasn't directly included (iirc it is what runs djlint) for either not being able to be manually run (yet we added editorconfigchecker in the callout, and technically djlint can be run by itself) or because in the jumble of moving docs and the CI and linter updating it was just got forgotten.

The ideal solution to this would be adding it into the information callout in point 10 of that technical section I linked above, where we already mention editorconfigchecker. Probably be good to include a full list of the relevant website CI tools that are ran to be sure. (Relevant file and lines in the repository: https://github.com/bevyengine/bevy-website/blob/main/content/learn/contribute/helping-out/writing-docs.md?plain=1#L229-L231)

For a list of what is currently ran on PRs, check out https://github.com/bevyengine/bevy-website/blob/main/.github/workflows/ci.yml.