Compatibility documentation (#312)

* Add compatiblity documentation

Author: Christoffer-Cortes

README.md

@@ -76,6 +76,7 @@ Visit [Eiffel Community](https://eiffel-community.github.io) to get started and
     - [**Authentication**](wiki/markdown/authentication.md)
     - [**Subscriptions**](wiki/markdown/subscription-API.md)
     - [**Download files**](wiki/markdown/download-files.md)
+1. [**Compatibility**](wiki/markdown/compatibility.md)
 1. [**Known limitations**](wiki/markdown/known-limitations.md)
 
 **Eiffel Intelligence documentation** [**can be found here**](https://eiffel-community.github.io/eiffel-intelligence/)

wiki/markdown/compatibility.md

@@ -0,0 +1,83 @@
+# Compatibility
+
+We recommend using the latest version of back-end and front-end whenever possible. However, this page contains a compatibility matrix and notes when pairing different versions.
+
+|                      |Front-end ➡           |                      |                      |                      |
+|---------------------:|:--------------------:|:--------------------:|:--------------------:|:--------------------:|
+|**Back-end ⬇**        |                 1.0.0|                 1.0.1|                 1.0.2|                 1.0.3|
+|[1.0.0](#back-end-100)|[✔️️](#front-end-100)   |[✔️️](#front-end-101)   |[✅](#front-end-102)  |[✅](#front-end-103)  |
+|[1.0.1](#back-end-101)|[✔️️](#front-end-100-1) |[✔️️](#front-end-101-1) |[✅](#front-end-102-1)|[✅](#front-end-103-1)|
+|[1.0.2](#back-end-102)|[❕](#front-end-100-2)|[✅](#front-end-101-2)|[✔️️](#front-end-102-2) |[✔️️](#front-end-103-2) |
+
+✔️️ Yes | ✅ Yes, minor Issue | ❕ Yes, medium Issue | ❌ No, major Issue
+<br>
+<br>
+## Back-end: 1.0.0
+#### Front-end: 1.0.0
+Compatible: ✔️️ Yes
+
+Notes: -
+
+#### Front-end: 1.0.1
+Compatible: ✔️️ Yes
+
+Notes: -
+
+#### Front-end: 1.0.2
+Compatible: ✅ Yes, minor Issue
+
+Notes:
+- Documentation is based on the [Agen](https://github.com/eiffel-community/eiffel/blob/master/eiffel-syntax-and-usage/versioning.md#versioning) version of the Eiffel protocol but it’s still functional since the jmespath reference to purl package instead of gav does not change subscription structure.
+
+#### Front-end: 1.0.3
+Compatible: ✅ Yes, minor Issue
+
+Notes:
+- Documentation is based on the [Agen](https://github.com/eiffel-community/eiffel/blob/master/eiffel-syntax-and-usage/versioning.md#versioning) version of the Eiffel protocol but it’s still functional since the jmespath reference to purl package instead of gav does not change subscription structure.
+
+## Back-end: 1.0.1
+#### Front-end: 1.0.0
+Compatible: ✔️️ Yes
+
+Notes: -
+
+#### Front-end: 1.0.1
+Compatible: ✔️️ Yes
+
+Notes: -
+
+#### Front-end: 1.0.2
+Compatible: ✅ Yes, minor Issue
+
+Notes:
+- Documentation is based on the [Agen](https://github.com/eiffel-community/eiffel/blob/master/eiffel-syntax-and-usage/versioning.md#versioning) version of the Eiffel protocol but it’s still functional since the jmespath reference to purl package instead of gav does not change subscription structure.
+
+#### Front-end: 1.0.3
+Compatible: ✅ Yes, minor Issue
+
+Notes:
+- Documentation is based on the [Agen](https://github.com/eiffel-community/eiffel/blob/master/eiffel-syntax-and-usage/versioning.md#versioning) version of the Eiffel protocol but it’s still functional since the jmespath reference to purl package instead of gav does not change subscription structure.
+
+## Back-end: 1.0.2
+#### Front-end: 1.0.0
+Compatible: ❕ Yes, medium Issue
+
+Notes:
+- Documentation is based on the [Toulouse](https://github.com/eiffel-community/eiffel/blob/master/eiffel-syntax-and-usage/versioning.md#versioning) version of the Eiffel protocol but it’s still functional since the jmespath reference to gav package instead of purl does not change subscription structure.
+- Multiple e-mail recipients are not supported through the front-end subscription form. This becomes possible to do from front-end version [1.0.1](https://github.com/eiffel-community/eiffel-intelligence-frontend/releases/tag/1.0.1) and forward.
+
+#### Front-end: 1.0.1
+Compatible: ✅ Yes, minor Issue
+
+Notes:
+- Documentation is based on the [Toulouse](https://github.com/eiffel-community/eiffel/blob/master/eiffel-syntax-and-usage/versioning.md#versioning) version of the Eiffel protocol but it’s still functional since the jmespath reference to gav package instead of purl does not change subscription structure.
+
+#### Front-end: 1.0.2
+Compatible: ✔️️ Yes
+
+Notes: -
+
+#### Front-end: 1.0.3
+Compatible: ✔️️ Yes
+
+Notes: -