add visrc and lithaskell lexer

config/vis/lexers/lithaskell.lua

@@ -0,0 +1,18 @@
+local l = require('lexer') 
+local token = l.token 
+local S = lpeg.S
+
+local M = {_NAME = 'lithaskell'} 
+
+local haskell = l.load('haskell') 
+local start_rule = token(l.STYLE_EMBEDDED, l.starts_line(S('><'))) 
+local end_rule = token(l.STYLE_EMBEDDED, l.newline) 
+
+local line = token(l.COMMENT, l.nonnewline^1)
+M._rules = {
+	{ 'comment', line }
+}
+
+l.embed_lexer(M, haskell, start_rule, end_rule) 
+
+return M