change(gridsome): add redirects from deprecated singer-specific detail pages

[aaronsteers]

We previously hosted Singer-specific detail pages for extractors and loaders.

We can redirect all of these endpoints to the generic plugin endpoints.

E.g.

• https://hub.meltano.com/taps/postgres -> https://hub.meltano.com/extractors/postgres
  • or https://hub.meltano.com/extractors/tap-postgres
• https://hub.meltano.com/taps/postgres--singer-io -> https://hub.meltano.com/extractors/tap-postgres--singer-io

[rwfeather]

Pasting from another comment I made:

@rwfeather - Is there a simple means to add these redirects?

• Update the netlify config netlify.toml with a redirect rule using a splat in the path
• Create "pages" that have the desired path (/singer/taps/*, /singer/target/*) while using the same underlying component to render the page. You can see an example of this method in gridsome.server.js 187:219

  // Create default variant pages
  api.createPages(async ({ createPage, graphql }) => {
    const defaultPlugins = await graphql(`...`)

    Object.keys(defaultPlugins.data).forEach((query) => {
      // For each default plugin we create an extra page one-level up
      defaultPlugins.data[query].edges.forEach(({ node }) => {
        createPage({
          // Remove the variant part of the path
          path: node.path.split("--")[0],
          // And send it to the same rendering template
          component: `./src/templates/Plugins.vue`,
          context: {
            id: node.id,
            // This is the path given to the `page-query` to do the lookup
            path: node.path,
            name: node.name,
          },
        });
      });
    });

For the second method, If there's any conditional rendering we want to do on the plugin page, it'll be possible to add something like an isSinger to the context object.

First method will be a lot lower-code and easier.

[aaronsteers]

As noted in https://github.com/meltano/hub/issues/793#issuecomment-1254240358:

@rwfeather - We are approved to remove these:

1. The JSON API endpoints for taps and targets. (Users will be recommended to use the newer API which covers all meltano plugin types.)

2. The Singer tap/target index and detail pages. (Redirect to 'extractor'/'loader' equivalents.)

   • Related follow-on: feat(gridsome): add "standalone usage" section to main plugins pages #821

[rwfeather]

Resolved in #824