Include info about HELEO branch, update versions

Signed-off-by: Agis Zisimatos <agzisim@gmail.com>

README.md

@@ -11,6 +11,7 @@ More details about versioning (Go/NoGo is referred to production of this version
 | [Gerber - 0.1.1](https://gitlab.com/librespacefoundation/satnogs-comms/satnogs-comms-hardware/-/releases/0.1.1-production) | [Report](https://gitlab.com/librespacefoundation/satnogs-comms/satnogs-comms-hardware/-/wikis/SatNOGS-COMMS-v0.1.1,-assembly-changes) | NoGo | [Experiment - 0.1.1](https://gitlab.com/librespacefoundation/satnogs-comms/satnogs-comms-hardware/-/wikis/home#satnogs-comms-v011) | N/A |
 | [Gerber - 0.2.1](https://gitlab.com/librespacefoundation/satnogs-comms/satnogs-comms-hardware/-/releases/0.2.1-assembly-1), [iBom - 0.2.1](https://gitlab.com/librespacefoundation/satnogs-comms/satnogs-comms-hardware/-/releases/0.2.1-assembly-1) | [Report](https://gitlab.com/librespacefoundation/satnogs-comms/satnogs-comms-hardware/-/wikis/SatNOGS-COMMS-v0.2.1-bug-report) | NoGo |[Experiment - 0.2.1](/uploads/177fbdbe55f0e27b0d8c33624cb746da/test-report.pdf), [Environmental Experiment - 0.2.1](/uploads/f2a2fe56697624136354e35655c860d5/environmental-test-report.pdf), [Power Consumption Table - 0.2.1](https://cloud.libre.space/s/3ajfRzbSNGH4o7m) | N/A |
 | [Gerber - 0.3](https://gitlab.com/librespacefoundation/satnogs-comms/satnogs-comms-hardware/-/releases/0.3-production-1), [iBom - 0.3](https://gitlab.com/librespa99cefoundation/satnogs-comms/satnogs-comms-hardware/-/releases/0.3-assembly-1) | [Report](https://gitlab.com/librespacefoundation/satnogs-comms/satnogs-comms-hardware/-/wikis/SatNOGS-COMMS-v0.3.0-bug-report) | NoGo | [Experiment - 0.3](/uploads/762667179a81d40d56f5acf71dfddb9a/test-report.pdf) | [FM software for the Curium-1 satellite on the Ariane 6 maiden flight](https://gitlab.com/librespacefoundation/satnogs-comms/satnogs-comms-software-mcu/-/releases/curium-1) |
+| [Fabrication and PCBA files - 0.3.1](https://gitlab.com/librespacefoundation/satnogs-comms/satnogs-comms-hardware/-/releases/0.3.1-assembly-2) | [Known issues section](https://gitlab.com/librespacefoundation/satnogs-comms/satnogs-comms-hardware/-/releases/0.3.1-assembly-2) | Go | [Experiment - 0.3.1](https://gitlab.com/librespacefoundation/satnogs-comms/satnogs-comms-design-doc/-/releases/1.5.2) | [SatNOGS COMMS Software - Commit Hash: 74dd552aef7a65cd7b1f169f5c3a85aeccf399f6](https://gitlab.com/librespacefoundation/satnogs-comms/satnogs-comms-software-mcu) |
 
 We follow [Semantic Versioning 2.0.0](https://semver.org/).
 
@@ -24,6 +25,16 @@ This is a KiCAD project thus merging can be tricky.
 Coordinate with project engineers before starting any changes and take look at issues.
 Also follow [contribution guide](CONTRIBUTING.md).
 
+### Branches
+Master or Main branch is development brach of SatNOGS COMMS which contain implementation of
+general requirements as specified by the beginning of project.
+
+Other branches that are specified in readme (as variants) are used for implementation of other missions that
+do not follow the initial requirments.
+
+Variants:
+* HELEO Mission, repurpose S-Band receiver to VHF receiver. Also it uses a different sub-system interface,
+instead of PC-104 it uses 2 different Gecko Harwin connectors. This variant is based on v0.3.2 release.
 
 ### EDA
 KiCAD 8