Create a manual section about Tor Browser for Android

We need to create a manual section about Tor Browser for Android.

So, let's start creating a section about Tor Browser for Android with:

• Introduction talking about Orbot+Orfox and now Tor Browser for Android.
• How to install:

• The Guardian Project repository
• Google Play
• Advanced: .apk

• How to use bridges and known bugs - https://trac.torproject.org/projects/tor/ticket/30767
• How to change identity and features that aren't available
• Troubleshooting