feat: github-api-url (#88)

closes #77

---------

Co-authored-by: Parker Brown <17183625+parkerbxyz@users.noreply.github.com>

post.js

@@ -5,12 +5,9 @@ import core from "@actions/core";
 import { post } from "./lib/post.js";
 import request from "./lib/request.js";
 
-post(
-  core,
-  request.defaults({
-    baseUrl: process.env["GITHUB_API_URL"],
-  })
-).catch((error) => {
+const baseUrl = core.getInput("github-api-url").replace(/\/$/, "");
+
+post(core, request.defaults({ baseUrl })).catch((error) => {
   /* c8 ignore next 3 */
   console.error(error);
   core.setFailed(error.message);