Add versioning strategy doc

(cherry picked from commit 524908b4f29dfa4f1b195bac7e22b553b9f48a76)

README.md

@@ -16,6 +16,7 @@ _The official repository URL for this repo is https://code.videolan.org/videolan
 - [Samples](#samples)
 - [Quick API overview](#quick-api-overview)
 - [Roadmap](#roadmap)
+- [Versioning](versioning.md)
 - [Contribute](#contribute)
 - [Communication](#communication)
     - [Forum](#forum)

VERSIONING.md

+# Versioning
+
+_This strategy applies to all LibVLCSharp [nuget packages](https://www.nuget.org/profiles/videolan) (Forms, etc.)._
+
+## Versioning strategy
+
+### We are tied to the libvlc versioning as this binding targets the libvlc public API
+
+### We will follow its major version (i.e. libvlc 3.x -> LibVLCSharp 3.x and so on)
+This makes it easier for people to understand and use the wrapper with libvlc, on all platforms.
+
+#### 0.x versions
+
+Initial LibVLCSharp releases were 0.x versions and target libvlc 3. It's getting stable now, though some APIs might still change (notably `VideoView` public API). When we consider it ready, we will move the LibVLCSharp package version to 3.x and 4.x.
+
+## Long Term Support (LTS)
+
+### We will maintain up to 2 major libvlc versions at the same time, using 2 different branches, starting with libvlc 3
+
+So when libvlc 4 gets released, we will maintain both LibVLCSharp 3.x and LibVLCSharp 4.x using the same nuget package id. When libvlc 5 lands, it is likely that we remove support for libvlc 3. We will still accept PRs and contributions from the community for older LibVLCSharp versions.
+
+## Breaking changes
+
+### Since our major version (i.e. [1].0.0) is tied to the libvlc major version, if we need to introduce breaking changes in the wrapper, we will bump the minor version (i.e. 1.[1].0) and reserve the last number (i.e. 1.1.[1]) for improvements and general maintenance (non breaking API changes).
\ No newline at end of file