chore: add release-pr workflow

.github/version-pr/action.yml

@@ -0,0 +1,8 @@
+name: "Determine version"
+description: "Determines npm package version based on PR number and commit SHA"
+outputs:
+  version:
+    description: "npm package version"
+runs:
+  using: "node16"
+  main: "index.js"

.github/version-pr/index.js

@@ -0,0 +1,19 @@
+// This is based on the work done by the next-auth team.
+const fs = require("fs")
+const path = require("path")
+const core = require("@actions/core")
+
+try {
+  const packageJSONPath = path.join(process.cwd(), "packages/cli/package.json")
+  const packageJSON = JSON.parse(fs.readFileSync(packageJSONPath, "utf8"))
+
+  const sha8 = process.env.GITHUB_SHA.substring(0, 8)
+  const prNumber = process.env.PR_NUMBER
+
+  const packageVersion = `0.0.0-pr.${prNumber}.${sha8}`
+  packageJSON.version = packageVersion
+  core.setOutput("version", packageVersion)
+  fs.writeFileSync(packageJSONPath, JSON.stringify(packageJSON))
+} catch (error) {
+  core.setFailed(error.message)
+}