Fixed HTML and JavaScript error

[mayuribotre15]

I have fixed all the HTML and JavaScript errors.

[mayuribotre15]

I have solved all the following error:
(If still showing error "DevTools failed to load SourceMap: Could not load content net::ERR_HTTP_RESPONSE_CODE_FAILURE"

Open Developer tools or inspect by right-clicking on-page,
go to "Settings" for Developer Tools,
then uncheck Enable JavaScript Source maps and Enable CSS Source maps under the "Sources" settings.
Restart Browser)

The original index.html file has an error at line 461.

• Uncaught (in promise) TypeError: Failed to register a ServiceWorker: The URL protocol of the current origin ('null') is not supported. at index.html:461

The service-worker.js also has an error such as

1. Uncaught (in promise) TypeError: Failed to execute 'Cache' on 'addAll': Request failed

2. DevTools failed to load SourceMap: Could not load content for file:///D:/Mayuri/Front%20End%20Developer/Github/opensourcediversity.org/vendor/popper.min.js.map: System error: net::ERR_FILE_NOT_FOUND

3. DevTools failed to load SourceMap: Could not load content for file:///D:/Mayuri/Front%20End%20Developer/Github/opensourcediversity.org/vendor/bootstrap.min.js.map: System error: net::ERR_FILE_NOT_FOUND

4. 1f33c.png:1 Failed to load resource: net::ERR_FILE_NOT_FOUND

5. DevTools failed to load SourceMap: Could not load content for file:///D:/Mayuri/Front%20End%20Developer/Github/opensourcediversity.org/vendor/bootstrap.min.css.map: System error: net::ERR_FILE_NOT_FOUND