[Docs] Remove apache configuration

Summary:
Update documentation around Apache as it's no longer necessary
for local development.

Test Plan:
Steps:

• Launch simulator
• Delete existing Comm app (Hold press on application, then select "Remove App", confirm with "Delete App")
• Update commapp_url.json and landing_url.json as described in diff (or delete them, and run nix develop)
• Restart yarn dev from native/, and yarn-dev from keyserver/
• Run simulator again

Rendered docs: https://github.com/CommE2E/comm/blob/jonringer/squadcal-apache/docs/dev_environment.md#urls

Reviewers: ashoat, varun

Reviewed By: ashoat, varun

Subscribers: tomek, atul

Differential Revision: https://phab.comm.dev/D5848