DOC: added link to feature list in README

     align folder structure in README w/ 5G-NR new folders
Signed-off-by: Raphael Defosseux <raphael.defosseux@eurecom.fr>

README.md

@@ -13,6 +13,7 @@ Please see [NOTICE](NOTICE.md) file for third party software that is included in
 
 # Where to Start #
 
+ *  [The implemented features](./doc/FEATURE_SET.md)
  *  [How to build](./doc/BUILD.md)
  *  [How to run the modems](./doc/RUNMODEM.md)
 
@@ -22,38 +23,51 @@ The OpenAirInterface (OAI) software is composed of the following parts:
 
 <pre>
 openairinterface5g
-├── ci-scripts: Meta-scripts used by the OSA CI process. Contains also configuration files used day-to-day by CI.
-├── cmake_targets: Build utilities to compile (simulation, emulation and real-time platforms), and generated build files
-├── common : Some common OAI utilities, other tools can be found at openair2/UTILS
-├── doc : Contains an up-to-date feature set list
-├── LICENSE
-├── maketags : Script to generate emacs tags
+├── ci-scripts        : Meta-scripts used by the OSA CI process. Contains also configuration files used day-to-day by CI.
+├── cmake_targets     : Build utilities to compile (simulation, emulation and real-time platforms), and generated build files.
+├── common            : Some common OAI utilities, other tools can be found at openair2/UTILS.
+├── doc               : Contains an up-to-date feature set list and starting tutorials.
+├── executables       : Top-level executable source files.
+├── LICENSE           : License file.
+├── maketags          : Script to generate emacs tags.
 ├── nfapi             : Contains the NFAPI code. A local Readme file provides more details.
-├── openair1 : 3GPP LTE Rel-10/12 PHY layer + PHY RF simulation. A local Readme file provides more details.
-├── openair2 : 3GPP LTE Rel-10 RLC/MAC/PDCP/RRC/X2AP + LTE Rel-14 M2AP implementation.
-    ├── COMMON
-    ├── DOCS
-    ├── ENB_APP
-    ├── LAYER2/RLC/ with the following subdirectories: UM_v9.3.0, TM_v9.3.0, and AM_v9.3.0. 
-    ├── LAYER2/PDCP/PDCP_v10.1.0.
-    ├── NETWORK_DRIVER
-    ├── PHY_INTERFACE
-    ├── RRC/LITE
-    ├── UTIL
-    ├── X2AP
-    ├── M2AP
-    ├── MCE_APP
-├── openair3: 3GPP LTE Rel10 for S1AP, NAS GTPV1-U for both ENB and UE.
-    ├── COMMON
-    ├── DOCS
-    ├── GTPV1-U
-    ├── NAS
-    ├── S1AP
-    ├── M3AP
-    ├── SCTP
-    ├── SECU
-    ├── UDP
-    ├── UTILS
-└── targets: Top-level wrappers for unitary simulation for PHY channels, system-level emulation (eNB-UE with and without S1), and realtime eNB and UE and RRH GW.
+├── openair1          : 3GPP LTE Rel-10/12 PHY layer / 3GPP NR Rel-15 layer. A local Readme file provides more details.
+│   ├── PHY
+│   ├── SCHED
+│   ├── SCHED_NBIOT
+│   ├── SCHED_NR
+│   ├── SCHED_NR_UE
+│   ├── SCHED_UE
+│   └── SIMULATION    : PHY RF simulation.
+├── openair2          : 3GPP LTE Rel-10 RLC/MAC/PDCP/RRC/X2AP + LTE Rel-14 M2AP implementation. Also 3GPP NR Rel-15 RLC/MAC/PDCP/RRC/X2AP.
+│   ├── COMMON
+│   ├── DOCS
+│   ├── ENB_APP
+│   ├── F1AP
+│   ├── GNB_APP
+│   ├── LAYER2/RLC/   : with the following subdirectories: UM_v9.3.0, TM_v9.3.0, and AM_v9.3.0.
+│   ├── LAYER2/PDCP/PDCP_v10.1.0
+│   ├── M2AP
+│   ├── MCE_APP
+│   ├── NETWORK_DRIVER
+│   ├── NR_PHY_INTERFACE
+│   ├── NR_UE_PHY_INTERFACE
+│   ├── PHY_INTERFACE
+│   ├── RRC
+│   ├── UTIL
+│   └── X2AP
+├── openair3          : 3GPP LTE Rel10 for S1AP, NAS GTPV1-U for both ENB and UE.
+│   ├── COMMON
+│   ├── DOCS
+│   ├── GTPV1-U
+│   ├── M3AP
+│   ├── MME_APP
+│   ├── NAS
+│   ├── S1AP
+│   ├── SCTP
+│   ├── SECU
+│   ├── TEST
+│   ├── UDP
+│   └── UTILS
+└── targets           : Top-level wrappers for unitary simulation for PHY channels, system-level emulation (eNB-UE with and without S1), and realtime eNB and UE and RRH GW.
 </pre>
-