Endpoint: move HTTP header to a GET parameter (#138)

Send `api-version=` querystring parameter instead of a HTTP header
`X-RTD-Hosting-Integrations-Version` as discussed.

* Requires: readthedocs/readthedocs.org#10753

Author: humitos

dist/readthedocs-addons.js

@@ -1,4 +1,4 @@
-import { CLIENT_VERSION } from "./utils";
+import { CLIENT_VERSION, ADDONS_API_VERSION } from "./utils";
 
 /**
  * Load Read the Docs configuration from API endpoint.
@@ -9,6 +9,8 @@ export function getReadTheDocsConfig() {
     "/_/addons/?" +
     new URLSearchParams({
       url: window.location.href,
+      "client-version": CLIENT_VERSION,
+      "api-version": ADDONS_API_VERSION,
     });
 
   // Retrieve a static JSON file when working in development mode
@@ -18,7 +20,6 @@ export function getReadTheDocsConfig() {
 
   return fetch(url, {
     method: "GET",
-    headers: { "X-RTD-Hosting-Integrations-Version": CLIENT_VERSION },
   }).then((response) => {
     if (!response.ok) {
       console.debug("Error parsing configuration data");

dist/readthedocs-addons.js.map

@@ -11,6 +11,7 @@ export function isReadTheDocsEmbedPresent() {
 }
 
 export const CLIENT_VERSION = packagejson.version;
+export const ADDONS_API_VERSION = "0";
 
 export const domReady = new Promise((resolve) => {
   if (