Add Rust programming language (#179)

diagrams/programming/language.py

@@ -68,6 +68,10 @@ class Ruby(_Language):
     _icon = "ruby.png"
 
 
+class Rust(_Language):
+    _icon = "rust.png"
+
+
 class Swift(_Language):
     _icon = "swift.png"
 

docs/nodes/programming.md

@@ -36,5 +36,6 @@ Node classes list of programming provider.
 - **diagrams.programming.language.Python**
 - **diagrams.programming.language.R**
 - **diagrams.programming.language.Ruby**
+- **diagrams.programming.language.Rust**
 - **diagrams.programming.language.Swift**
 - **diagrams.programming.language.Typescript**, **TypeScript** (alias)