Add fiscal sponsor projects to the site

[NPDebs]

This PR fixes issue #869.
OLS's index fiscally sponsored community, RSE-AUNZ, has been added to the appropriate page (i.e .../open-incubator/fiscal-hosting/).

Changes made:

• Created a new fiscal_communities array within the _data/community.yaml file and added data about RSE-AUNZ.
• Wrote logic to add RSE-AUNZ to the bottom of the fiscal-hosting page.

Screenshot:

Note for reviewers:

• Does this count as mvp or robust structure (as requested in issue add fiscal sponsor projects to the site - robust infrastructure.  #870)?

Thanks for the review!

FOR CONTRIBUTOR

• I have read the CONTRIBUTING.md document

PR Type:

• This PR adds a new blog post
• This PR does something else (explain above)

FOR REVIEWERS

Thanks for taking the time to review! ❤️

Here are the list of things to make sure of:

• The website builds (a check will fail if not)
• All images have been added within the Pull Request and they have Alt text
• If there are paragraphs or text, the key messages are highlighted
• All internal links (within OLS website) use the {% link path_to_file.md %} format
• The preview corresponds to the changes described in the Pull Request
• The code is tidy and passes the linting tests

[netlify]

✅ Deploy Preview for ols-bebatut ready!

Name	Link
🔨 Latest commit	7cfc3e8
🔍 Latest deploy log	https://app.netlify.com/sites/ols-bebatut/deploys/671920c2764bb60008038bd7
😎 Deploy Preview	https://deploy-preview-889--ols-bebatut.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.

[bebatut]

Have you tried if link and email variable from the _config.yaml work there?

[NPDebs]

Yeah. It typically doesn't work in the yaml frontmatter.

[yochannah]

visually the change looks good - I'll merge but leave the tag to note that Bérénice may wish to review further.