Fix permalinks and redirects

[ajschmidt8]

Recording two items that we should fix here so I don't forget:

• Remove all redundant permalink directives
  • Example here. This is redundant because the file's location in the Jekyll project dictates its final URL. Since the file exists in the root directory and is named api.md, then its path will be /api/ by default.
  • Wherever we do need to overwrite the permalink, we should ensure we use a trailing slash (e.g. api/) so that "pretty" URLs are generated (e.g. /api/ vs. /api.html). This will ensure we're consistent with the Jekyll config option here: https://github.com/rapidsai/docs/blob/c4992e07ee524e98fd0ddfea3ab5724816cfc25c/_config.yml#L10
• Add a server-side redirect for /deployments/.
  • This used to be a client-side redirect before we scrubbed the api/ and deployment/ folders from the git history (src). Therefore we should add it back as a server-side redirect.
  • This will require adding a _redirects file for Netlify (like this one from the main website) to our docs site and then ensuring it is copied into Jekyll's _site folder upon deploy.

cc: @exactlyallan @jacobtomlinson

[ajschmidt8]

The point about the _redirects file will require some tinkering.

Right now we have separate build/deploy processes for PR preview environments vs. production deploys:

• PR preview environments: use Netlify's automatic deploy feature for PRs. They just run jekyll build and deploy the result (without pulling any docs from S3).
• Production deploys: use this new GHAs workflow to build the Jekyll site, run our hacky post-processing scripts (which we will remove in the future!!), and then manually deploy the result via Netlify's CLI

We can run different scripts for these different environments by utilizing a netlify.toml file (docs here) to ensure that the PR preview environments don't try to pull any files from S3 (since Netlify's CI machines won't have access to S3).

[ajschmidt8]

Closing since this issue is superseded by our efforts to migrate docs.rapids.ai into rapids.ai.