Update README.md

README.md

-Syntax-derived editor for ES Tools
+# Syntax-derived editor for ES Tools
+
+#### Editors
+* OSS
+  * Contract
+  * Contract.Expression
+* NuSMV
+* Fei
+* Tfpg
+* Tfpga
+* CleanC
+  * C.Statement
+  * C.Expression
+
+Following a (not exhaustive) representation of the grammars hierarchy (some are missing, i.e. Tfpg, Tfpga, and CleanC)
+![Grammar Hierarchy](docs/Grammars%20Hierarchy.png)
 
 **Project Build instruction:**