[GRASS-git] [OSGeo/grass] 1ed8b2: g.extension: add branch option (#1130)

[Stefan Blumentrath]

  Branch: refs/heads/master
  Home:   https://github.com/OSGeo/grass
  Commit: 1ed8b2c5c636ac9f81c4013ab766b3379d16f0c7
      https://github.com/OSGeo/grass/commit/1ed8b2c5c636ac9f81c4013ab766b3379d16f0c7
  Author: Stefan Blumentrath <stefan.blumentrath at gmx.de>
  Date:   2020-12-02 (Wed, 02 Dec 2020)

  Changed paths:
    M scripts/g.extension/g.extension.html
    M scripts/g.extension/g.extension.py

  Log Message:
  -----------
  g.extension: add branch option (#1130)

* add branch option

* use main as default branch

* try download add-on from the master branch if the main branch does not exist

fix install add-on e.g.: g.extension r.example.plus url='https://github.com/wenzeslaus/r.example.plus'

* try download add-ons files paths json file from the master branch if the main branch doesn't exist

e.g. g.extension -j

* add example with branch

* consolidate messages

* fix a flake8 issue

* use format correctly

* improve message

Co-authored-by: Markus Neteler <neteler at gmail.com>

* improve message

Co-authored-by: Markus Neteler <neteler at gmail.com>

Co-authored-by: Tomas Zigo <50632337+tmszi at users.noreply.github.com>
Co-authored-by: Markus Neteler <neteler at gmail.com>