Use Frontmatter Title to Allow Automatic Listings

[hacdias]

Context: ipfs/specs#385 (comment).

Currently, the specs files do not use the title in the frontmatter, but in the file itself, which does not happen with the remaining pages. This makes generating listings harder.

Proposal is to add title and description to the frontmatter of the specs. This will allow us to automatically generate the listings of the pages, instead of keeping them manually.

{%- for post in collections.all -%}
  <li>{{ post.data.title }}</li>
{%- endfor -%}

Then, we can add a tag: ipip to the IPIPs and iterate over collections.ipips.

[hacdias]

@lidel I think this is something we should really do in terms of consistency and before ipfs/specs#385. Otherwise, we can also perhaps introduce some other way of processing this in a different way such that we have access to post listings per directory. That could potentially be useful.

[lidel]

Agree, we need this for ipfs/specs#385.

@hacdias perhaps do title and description for now? <meta name="description" (..) will improve how specs are presented in search results (https://developers.google.com/search/docs/appearance/snippet).