Add v2.2.0 release notes

# RELEASE NOTES: #

## [v2.2.0](https://gitlab.eurecom.fr/oai/openairinterface5g/-/tags/v2.2.0) -> November 2024. ##

General 5G improvements (both gNB and UE):

- Make standalone mode (SA) the default (see [`RUNMODEM.md`](doc/RUNMODEM.md))

- Experimental support for FR2 operation

- Support for GEO NTN and simulation of GEO satellite channel in RFsimulator

  (see [`RUNMODEM.md`](doc/RUNMODEM.md))

- Support 2-step RA

- Add optional LTTng logger in logging module (see

  [`lttng_logs.md`](common/utils/LOG/DOC/lttng_logs.md))

- Support for YAML-based config files (alongside libconfig) (see

  [`gnb.sa.band78.106prb.rfsim.yaml`](ci-scripts/conf_files/gnb.sa.band78.106prb.rfsim.yaml) and

  [`nrue.uicc.yaml`](ci-scripts/conf_files/nrue.uicc.yaml))

- Add new L1 scope based on Dear ImGui (see [`readme.md`](openair1/PHY/TOOLS/readme.md))

- Allow cross-compilation on ARM (via SIMDE SIMD emulation library)

- Allow to build and run with clang

- Support/check for Linux capabilities, allow to run without sudo (see

  [`tuning_and_security.md`](doc/tuning_and_security.md))

- OAI does not modify CPU frequency and networking stack

  ([`tuning_and_security.md`](doc/tuning_and_security.md))

- Bugfixes in the entire stack (e.g.  #547, #663, #674, #687, #712, #736, #739,

  #741, #756, #762, #773, ...)

5G gNB:

- Support for FR2 interoperability with COTS UE (no beam switching supported yet)

- Add 4-layer DL MIMO (experimental)

- Add gNB Neighbour configuration and Mobility over F1 interface (see

  [`handover-tutorial.md`](doc/handover-tutorial.md))

- Enhance O-RAN FHI 7.2: (see [`ORAN_FHI7.2_Tutorial.md`](doc/ORAN_FHI7.2_Tutorial.md))

  * Support different bandwidths (40/60/80/100MHz) and antenna configs (1x1 up

    to 4x4) for Benetel/VVDN/LITEON RUs

  * Add support for multi-RU support (single-cell/distributed antenna)

- Support AMD T2 Telco card look-aside L1 accelerator (see

  [`LDPC_T2_OFFLOAD_SETUP.md`](doc/LDPC_T2_OFFLOAD_SETUP.md))

- Support Nvidia Aerial/ARC in-line L1 accelerator (see

  [`Aerial_FAPI_Split_Tutorial.md`](doc/Aerial_FAPI_Split_Tutorial.md))

- Various fixes for multi-UE operation: by default support of up to 16 UEs concurrently

- Documentation for

  - 5G MAC (see [`mac-usage.md`](doc/MAC/mac-usage.md))

  - 5G RRC (see [`rrc-usage.md`](doc/RRC/rrc-usage.md))

  - E1 (see [`E1-design.md`](doc/E1AP/E1-design.md))

  - F1 (see [`F1-design.md`](doc/F1AP/F1-design.md))

5G UE:

- Basic interoperability with COTS gNB (Nokia gNB)

- Implement PHR reporting

- Implement RRC re-establishment

- Implement PUCCH/PUSCH/SRS power control

- Implement UCI on PUSCH and aperiodic CSI reporting

- Support of cell search (within the selected UE bandwidth) (see [`RUNMODEM.md`](doc/RUNMODEM.md))

- Enhance connection control: implement timers, resync

- A lot of internal cleanup

This release also includes many fixes and documentation updates. See

`doc/README.md` in the repository for an overview of documentation.

## [v2.1.0](https://gitlab.eurecom.fr/oai/openairinterface5g/-/tags/v2.1.0) -> February 2024. ##

This release improves existing 5G support and adds various new features.