Add changelog, fix weird build failure

CHANGELOG.md

@@ -0,0 +1,5 @@
+# Changelog
+
+## 3.7.0
+
+- Make the `load` function idempotent

README.md

@@ -9,8 +9,6 @@ This library is a JavaScript client for [Fathom Analytics](https://usefathom.com
 
 Maintained with ♥️ by the [SavvyCal](https://savvycal.com/?utm_source=github&utm_medium=oss&utm_campaign=fathom-client) team
 
-[![sc-sticker](https://user-images.githubusercontent.com/341387/150855440-1a4122b4-b3c9-47b5-91ff-c0d73f421f84.svg)](https://savvycal.com/?utm_source=github&utm_medium=oss&utm_campaign=fathom-client)
-
 ## Installation
 
 Run the following to install in your project:

src/index.ts

@@ -25,7 +25,7 @@ export type EventOptions = {
 
 /**
  * @see https://usefathom.com/support/tracking-advanced
- **/ 
+ **/
 export type LoadOptions = {
   url?: string;
   auto?: boolean;
@@ -122,7 +122,7 @@ const checkDomainsAndWarn = (domains: string[]): void => {
 
 /**
  * Loads the Fathom script.
- * 
+ *
  * @param siteId - the id for the Fathom site.
  * @param opts - advanced tracking options (https://usefathom.com/support/tracking-advanced)
  */
@@ -143,7 +143,8 @@ export const load = (siteId: string, opts?: LoadOptions): void => {
   tracker.id = 'fathom-script';
   tracker.async = true;
   tracker.setAttribute('data-site', siteId);
-  tracker.src = opts?.url || 'https://cdn.usefathom.com/script.js';
+  tracker.src =
+    opts && opts.url ? opts.url : 'https://cdn.usefathom.com/script.js';
 
   if (opts) {
     if (opts.auto !== undefined)