Redirect to app root on dev server

[samuelmeuli]

Q	A
Fixed Issues?	Closes #113
Patch: Bug Fix?	No
Minor: New Feature?	Yes
Major: Breaking Change?	No
Tests Added + Pass?	No
Documentation Provided	Yes (code comments)
Any Dependency Changes?	No
License	Apache License, Version 2.0

Configures the Angular/React apps to automatically navigate to the app root (instead of /) in development mode. The app fails at the root with a very unhelpful error message, see #113 for details.

• React: I added a script to index.html similar to @ittaibaratz's in https://github.com/adobe/aem-spa-project-archetype/issues/113#issuecomment-542790405 but used location.pathname instead of location.href so it can work on any localhost port.
• Angular: Because environment variables aren't available in the HTML, I added the logic to the app itself. If the app is run in development mode and on localhost, the same redirection will be performed. I also configured the npm start to open the browser automatically (and removed some unnecessary CLI options).

[habansal]

@samuelmeuli Looks good to me. Do we need any Readme updates as well or will you take care of that via https://github.com/adobe/aem-spa-project-archetype/pull/119

[samuelmeuli]

@habansal I'd suggest merging the README PR first (maybe even to master), and I'll rebase this one on top of it and make the necessary changes

[samuelmeuli]

I've updated the READMEs in angular-app and react-app.