Sort object types before writing markdown file

[jeskew]

This PR sorts the object types written to generated markdown files alphabetically by name. It's an attempt to make PRs that alter what qualifies as a resource (e.g., #805) easier to review.

Currently, the order in which types appear in generated markdown files is determined by when they are used in a provider's swagger model. As a consequence, when a PR expands the definition of what qualifies as a resource, that can cause shapes to change position in the .md file, leading to a bunch of noise in the resulting diff, e.g.:

With a stable sort, the diff for .md files would just be insertions.

[jeskew]

I'm taking a look over the generated types from this (in #871) to make sure nothing unexpected is happening. If there's nothing surprising there, will merge and then run the type update workflow on main.

[jeskew]

All the log.out files in #871 had zero surprises, and I spot checked several markdown files to make sure objects were just being moved around. Everything looks hunky dory.

[majastrz]

This is a great change btw!