Explain docs-internal links in Renovate style guide

[HonkingGoose]

Describe the proposed change(s).

Explain the correct link format for links to docs-internal pages in the Renovate style guide.

Todos:

• [ ] Explain correct link format.
• [ ] Show examples of the correct link format.
• [ ] Explain how to confirm the link points to the right file, and right location in the file (anchor).
• [ ] Any helpful tips/tricks.

I'll let a maintainer write these docs, because I'm the one messing up the links every time... 🙈

Related discussion which was approved by @rarkins:

• 29565

[HonkingGoose]

@viceice is this something you want to work on? You usually get my bad links sorted out for me. 😉

[viceice]

when I find some time 🙈