Add release-pr workflow (#490)

* Add `release-pr` workflow

* Add comments

* fix quotes

scripts/release-pr.js

@@ -0,0 +1,21 @@
+const path = require("path");
+const { exec, getExecOutput } = require("@actions/exec");
+
+const { version } = require("../package.json");
+const tag = `v${version}`;
+const releaseLine = "pr-release";
+
+process.chdir(path.join(__dirname, ".."));
+
+(async () => {
+  await exec("git", ["checkout", "--detach"]);
+  await exec("git", ["add", "--force", "dist"]);
+  await exec("git", ["commit", "-m", tag]);
+
+  await exec("git", [
+    "push",
+    "--force",
+    "origin",
+    `HEAD:refs/heads/${releaseLine}`,
+  ]);
+})();