Bad links for browser customization

[motinis]

At https://loopkit.github.io/loopdocs/browser/custom-browser/#overview

The following links do not go to the right places:

• Overview (I think this should go to: https://www.loopandlearn.org/custom-code-browser-build/)
• template for main (https://www.loopandlearn.org/custom-code-browser-build/#template-main)
• template for dev (https://www.loopandlearn.org/custom-code-browser-build/#template-dev)

[marionbarker]

Thanks. There are more places that require an update to match the reorganized loopandlearn pages. Eric is extending his PR to cover them all.