README.md: clarify instructions (OSGeo#785)

* major text reorganization

Fixes OSGeo#784

README.md

@@ -1,17 +1,5 @@
 # GRASS Addons git repository
 
-## How to get write access here
-
-Read access is granted to the public, write access
-must be requested, see here for details:
-<https://trac.osgeo.org/grass/wiki/HowToContribute#WriteaccesstotheGRASSaddonsrepository>
-
-However, it is also possible to fork this repository, insert your AddOn or fix
-an existing one in a new branch and finally open
-a [pull request](https://help.github.com/en/articles/about-pull-requests).
-
-In either case, please read the submitting rules at the bottom of this page.
-
 ## How to get the AddOn code
 
 Clone of the entire AddOns git repository:
@@ -28,27 +16,38 @@ module:
 
 ## How to compile AddOn code
 
-### C code/Scripts, with GRASS source code on your computer
+### Compilation with GRASS GIS binaries on your computer
+
+In this case, compile GRASS AddOns modules into your installed GRASS code
+by setting `MODULE_TOPDIR` to where to the GRASS binaries are located:
+
+```bash
+make MODULE_TOPDIR=/usr/lib/grass/
+```
+
+### Compilation with GRASS GIS core source code locally compiled
 
-Preparations (assuming the source code in $HOME/grass/):
-(if you have already built GRASS from source you don't need to do this
-again. If adding to a binary install, the versions must match exactly.
-You need to git checkout the exact tag or commit used for the binary.)
+Preparations (assuming the [GRASS GIS core source code](https://github.com/OSGeo/grass)
+being stored in `$HOME/grass/` - if you have already built GRASS GIS core from
+source code you don't need to do this again. If adding to a binary install,
+the versions must match exactly. You need to `git checkout` the exact tag
+or commit used for the binary.)
 
 ```bash
+# GRASS GIS core source code
 ./configure # [optionally flags]
-make libs
+make
 ```
 
 The easiest way to compile GRASS AddOns modules into your GRASS code
-is by setting MODULE_TOPDIR on the fly to tell 'make' where to
+is by setting `MODULE_TOPDIR` on the fly to tell `make` where to
 find the prepared GRASS source code:
 
 ```bash
 make MODULE_TOPDIR=$HOME/grass/
 ```
 
-(adapt to your /path/to/grass/). Each module/script in the GRASS
+(adapt as needed to your `/path/to/grass/`). Each module/script in the GRASS
 AddOns git repository should have a Makefile to support easy
 installation.
 
@@ -59,29 +58,28 @@ make MODULE_TOPDIR=$HOME/grass/ install
 ```
 
 For system-wide installation this usually requires "root" privileges
-(so, also 'sudo' may help).
-
-### C code/Scripts, with GRASS binaries on your computer
+(so, also `sudo` may help).
 
-compile GRASS AddOns modules into your GRASS code by setting
-MODULE_TOPDIR to where to the GRASS binaries are located:
+## How to submit your contributions
 
-```bash
-make MODULE_TOPDIR=/usr/lib/grass/
-```
+While read access is granted to the public, for submissions you best fork
+this repository, insert your AddOn or fix an existing one in a new branch
+and finally open a [pull request](https://help.github.com/en/articles/about-pull-requests).
 
-## How to submit contributions
+If you aim at full write access, this must be formally requested, see here for details:
+<https://trac.osgeo.org/grass/wiki/HowToContribute#WriteaccesstotheGRASSaddonsrepository>
 
-To submit your GRASS GIS module here, please check
+In either case, please note the folloing submitting rules: To successfully submit your
+GRASS GIS AddOn module here, please check
 
 <https://grass.osgeo.org/development/>
 
-The submission must be compliant with the GRASS
+Your submission must be compliant with the GRASS
 submission rules as found in the GRASS source code
 and RFC2 (Legal aspects of submission):
 
 <https://trac.osgeo.org/grass/wiki/RFC>
 
 Also read submitting instructions before committing any changes!
 
-<https://trac.osgeo.org/grass/wiki/Submitting>
+<https://trac.osgeo.org/grass/wiki/Submitting>