Temporarily host REM on fly to fix the docs

[JAForbes]

Description

Fixes REM examples in the docs.

The documentation currently has a dead link as REM is no longer hosted on heroku. I think we should probably rewrite the example to not rely on an external service, but in the meantime I've hosted Leo's REM service on fly.io.

Motivation and Context

It's not good having broken documentation for the central example of the framework

How Has This Been Tested?

I updated the flems to use the new service and it worked. You can try it out here

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation change

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.
• I have updated docs/changelog.md

[dead-claudia]

Can you also do a search and replace on gh-pages similar to what we (read: Pat) did years ago to add the red deprecation notice banner to past versions, and then file a PR against gh-pages with that until we add a long-term solution?

[JAForbes]

Can you also do a search and replace on gh-pages similar to what we (read: Pat) did years ago to add the red deprecation notice banner to past versions, and then file a PR against gh-pages with that until we add a long-term solution?

Sorry missed this, can you link me to the PR where Pat did that and I'll do my best in a separate PR.

[dead-claudia]

@JAForbes I'll do it. I have some spare time.

[dead-claudia]

And fixed with a manual push: 487780f

Here's what I did, for future reference:

1. Run git checkout upstream gh-pages

2. Add /gh-pages-scripts to .git/info/exclude

3. Save the following script to ./gh-pages-scripts/fix-link.mjs:

   import * as fs from "node:fs/promises"
   import * as path from "node:path"
   import LZString from "lz-string"
   import walk from "ignore-walk"
   
   if (process.argv.length < 4) {
       console.error(`
   Usage: node ./gh-pages-scripts/fix-link.mjs [source] [replacement]
   
   Run with the current working directory set the root of to a \`gh-pages\`
   checkout.
   `)
   }
   
   const source = process.argv[2]
   const replacement = process.argv[3]
   
   const flemsPattern = /flems\.io\/#0=([A-Za-z0-9+-]+)/
   
   function flemsReplacer(_, data) {
       const parsed = JSON.parse(LZString.decompressFromEncodedURIComponent(data))
   
       if (Array.isArray(parsed.files)) {
           for (const file of parsed.files) {
               if (typeof file.name === "string") {
                   file.name = file.name.replaceAll(source, replacement)
               }
               if (typeof file.content === "string") {
                   file.content = file.content.replaceAll(source, replacement)
               }
           }
       }
   
       if (Array.isArray(parsed.links)) {
           for (const file of parsed.links) {
               if (typeof file.name === "string") {
                   file.name = file.name.replaceAll(source, replacement)
               }
               if (typeof file.url === "string") {
                   file.url = file.url.replaceAll(source, replacement)
               }
           }
       }
   
       return `flems.io/#0=${LZString.compressToEncodedURIComponent(JSON.stringify(parsed))}`
   }
   
   async function visitFile(file) {
       file = path.resolve(file)
       const contents = await fs.readFile(file, {encoding: "utf-8"})
   
       const replaced = contents
           .replaceAll(source, replacement)
           .replace(flemsPattern, flemsReplacer)
   
       if (replaced !== contents) {
           console.log(`Replaced ${file}`)
           await fs.writeFile(file, replaced, {encoding: "utf-8"})
       }
   }
   
   const files = await walk({
       path: process.cwd(),
       ignoreFiles: [".gitignore"],
   })
   
   Promise.all(Array.from(files, visitFile))

4. Run npm install ignore-walk lz-string

5. Run node ./gh-pages-scripts/fix-link.mjs rem-rest-api.herokuapp.com mithril-rem.fly.dev

6. Verify the file changes matches the changes in this issue.

7. Run git push upstream gh-pages