feat(node): add raspbian gen os (#589)

* Add Raspberry Pi logo for describing RPis.

* Added raspbian.png for Raspberry Pis.

* update raspbian.png for size

diagrams/generic/os.py

@@ -24,6 +24,10 @@ class LinuxGeneral(_Os):
     _icon = "linux-general.png"
 
 
+class Raspbian(_Os):
+    _icon = "raspbian.png"
+
+
 class Suse(_Os):
     _icon = "suse.png"
 

docs/nodes/generic.md

@@ -36,6 +36,7 @@ Node classes list of generic provider.
 - **diagrams.generic.os.Centos**
 - **diagrams.generic.os.IOS**
 - **diagrams.generic.os.LinuxGeneral**
+- **diagrams.generic.os.Raspbian**
 - **diagrams.generic.os.Suse**
 - **diagrams.generic.os.Ubuntu**
 - **diagrams.generic.os.Windows**