fix: add deno install root to path (#7)

src/install.js

@@ -1,3 +1,5 @@
+const os = require("os");
+const path = require("path");
 const process = require("process");
 const core = require("@actions/core");
 const tc = require("@actions/tool-cache");
@@ -33,6 +35,9 @@ async function install(version) {
   );
   core.info(`Cached Deno to ${newCachedPath}.`);
   core.addPath(newCachedPath);
+  const denoInstallRoot = process.env.DENO_INSTALL_ROOT ||
+    path.join(os.homedir(), ".deno", "bin");
+  core.addPath(denoInstallRoot);
 }
 
 /** @returns {string} */