Release documentation: (OpenSimulationInterface#382)

* Release documentation:

* Replace links to commit hash with link to release page

* replaced all commit hashs in release notes

Merge pull request OpenSimulationInterface#302 from OpenSimulationInt…

…erface/CarloVanDriestenBMW-patch-1

Adapt version file to release 3.1.2

Revert breakage in ce92c01 to CMake build of SO (OpenSimulationInterf…

…ace#301)

Commit ce92c01 changed the
open_simulation_interface target from being a shared library to a static
library (for which we already have the open_simulation_interface_static
target). This reverses that part of the patch.

Documentation3.1.0 v001 (OpenSimulationInterface#299)

* Unify comments.

Change HTML Documentation. Try to remove HTML tags, if possible.
Use only \ for doxygen tags (remove all @)
Add Unit tests to parse comments.

* Update osi_trafficsign.proto

Unify doxygen Format.
Dot at the end of 1mio sentences.

* Math Formulas

Add MathJax

* Update Math formulas

Merge Master Branch

Merge pull request OpenSimulationInterface#267 from OpenSimulationInt…

…erface/Moving-Objects-relative-velocity-definition

Update Definition solves OpenSimulationInterface#234

Merge pull request OpenSimulationInterface#202 from OpenSimulationInt…

…erface/review/pre-release

Reordering / Restructuring and much more!

Merge pull request OpenSimulationInterface#188 from OpenSimulationInt…

…erface/maintenance/v2.2.x-fixes

Maintenance/v2.2.x fixes

Merge pull request OpenSimulationInterface#59 from OpenSimulationInte…

…rface/feature/define-rain-and-fog

Resolve issue OpenSimulationInterface#54 (fog definition)

Merge pull request OpenSimulationInterface#40 from OpenSimulationInte…

…rface/contour2d

Contour2d

Merge pull request OpenSimulationInterface#11 from OpenSimulationInte…

…rface/change_version_numbering

Updated README.md for versioning definitions