Add GitHub stars badges to homepage and ontology page

[cthoyt]

Similar to #1687, Shields.io will generate all sorts of nice badges that give summary-level information on repositories that can be formatted in using the following markdown:

![GitHub Repo stars](https://img.shields.io/github/stars/:organization/:repository?style=social)

GitHub stars in some ways could be considered as a proxy for ontology usage and uptake, which would be useful for potential users/consumers.

A few examples:

Ontology	Repo	Badge
PLANA	obophenotype/planaria-ontology
CHEMINF	semanticchemistry/semanticchemistry
INO	INO-ontology/ino

Note: I'd be happy to provide the implementation of this if it gets positive feedback.

[matentzn]

Before you get to wild on this, just remember that there are a number of ontologies with proper version control not on GitHub. There will be some strong arguments against your proposal because it will put ontologies not on GitHub in an unfair disadvantage. I am not that worried, but prepare for that counterargument.

[cthoyt]

I looked for generating badges from GitLab and they're just not as well-supported in shields.io (and similar services).

It's also the case that non-GitHub repositories just aren't well-annotated in the OBO Foundry, so I'm not sure if the argument of lack of engagement from non-GitHub repositories is a reason not to support what most of the community is doing. Here's a summary of the "repository" annotations across the OBO Foundry:

System	Count	Percentage
GitHub	182	73.39
None	64	25.81
Other	1	0.4
GitLab	1	0.4

Code used to make this table (can be rerun anytime)

```python from collections import Counter from tabulate import tabulate from bioregistry.external.obofoundry import get_obofoundry counter = Counter() for prefix, data in get_obofoundry().items(): repository = data.get("repository") if repository is None: counter["None"] += 1 elif "github" in repository: counter["GitHub"] += 1 elif "gitlab" in repository: counter["GitLab"] += 1 else: counter["Other"] += 1 print(prefix, repository) n = sum(counter.values()) rows = [ (key, count, round(100 * count / n, 2)) for key, count in counter.most_common() ] print(tabulate(rows, headers=["System", "Count", "Percentage"], tablefmt="github")) ```

[matentzn]

There are still "None" ones? I thought you added repository tags to ever record for an active ontology?

[cthoyt]

No, I added one for every repository that I could parse the GitHub repository from the issue tracker annotation. I can do my best to automate stuff, but we need to communicate to repo owners that it's their responsibility to get this metadata into OBO Foundry if they want their work to (continue to be) be accessible/useful

[matentzn]

Yeah. Ok! I was so certain that everyone had an issue tracker now.. Must have been dreaming.