Add R language (#114)

Author: AlexPishchikov

drp.py

@@ -79,6 +79,7 @@ def base_activity(started = False):
     'png,jpg,jpeg,jfif,gif,webp': 'image',
     'py,pyx': 'python',
     'p,sp': 'pawn',
+    'r,rda,rdata,rds,rhistory' : 'r',
     'rb': 'ruby',
     'rs': 'rust',
     'sh,bat': 'shell',
@@ -121,6 +122,7 @@ def base_activity(started = False):
     'php',
     'pawn',
     'python',
+    'r',
     'scala',
     'svelte',
     'yara',