Prepend anchors 0.6

[jo-mueller]

The anchors that are autogenerated in the pre_build.py script (i.e., here on main) are generated in exactly the same way on all the other branches of ngff-spec, which leads to confusion with how anchors are resolved over at ngff (see also ome/ngff#607)

This solves it on main, but the fix will have to be ported over to the 0.1 ... 0.5 branches, too.

Another small issue I noted - the examples section lists its own index.md as part of the examples:

Which is fixed in ee4b168 here, too. Big screenshot for a small fix.

[github-actions]

Automated Review URLs

• Readthedocs

[jo-mueller]

@lubianat @clbarnes I think this would actually be important to get in before tagging 0.6 as part of the fix for ome/ngff#607. After 0.6 is tagged, we cannot change it because we cannot edit the tag.

We could (and probably should) archive 0.6 on a different branch though, so we can make these small build fixes for 0.6 in the future, too.

[clbarnes]

One thing to consider about the anchors is that the colons get normalised to hyphens in the built site, so maybe it's best to write them as hyphens in the first place to minimise confusion/ in case someone tries to differentiate two anchors by colon/hyphen?

[lubianat]

I approved it in all to allow merge and leave @jo-mueller to decide what to do with @clbarnes's comment (which makes sense)

I think though we should stop supporting changes on 0.1, 0.2 and 0.3 (unless they are security vulnerabilities)....