Add details about supported OSes and architectures (libcore and bindi…

…ngs)

README.md

@@ -139,7 +139,20 @@ Generating bindings is a several steps process:
 ```
 node ledger-core-samples/nodejs/tests/wallet-pool-test.js
 ```
-
+## Support
+
+###Libcore:
+Libcore can be built for following OSes:
+ - MacOS: minimum supported version is `macOS 9.0`, with `x86_64` architecture,
+ - Linux: Debian (stretch), Ubuntu and Arch are supported, with `x86_64` architecture,
+ - Windows: 64-bit architecture is built with `MSVC` (starting from Visual Studio 15), 32-bit is built with `MinGW`,
+ - iOS: `x86_64`, `armv7` and `arm64` architectures are supported, minimum supported version is `iOS 10.0`,
+ - Android: `x86`, `armeabi-v7a` and `arm64-v8a` architectures are supported, minimum supported version is `Android 7 (API 24)` (Java 8 is needed).
+###Bindings:
+ - NodeJS bindings:
+   - Please use `node` with version `>=8.4.0` and `<9.0.0` (other versions are not tested (yet)),
+   - Node-gyp is used to build native module and requires `python` with version `2.7.x`.
+
 ## Developement guidelines
 
 ### CI