antlr3.yaml: Add .g language

This adds the specification of antlr3

Closes #56

data/Language/antlr3.yaml

@@ -0,0 +1,40 @@
+identifier: antlr3
+creation_date: 2008
+full_name: Another Tool For Language Recognition
+grammar_file: https://github.com/antlr/grammars-v3
+aliases:
+  - antlr3
+extensions:
+  - g
+line_continuation:
+  - backslash
+  - vertbar
+delimiters:
+  # comment delimiters:
+  - double_slash
+  - multiline_slash_star
+  - multiline_double_slash_star
+  # string delimiters:
+  - single_quote_slash_escape
+  # block delimiters:
+  - curly_braces
+  - round_braces
+  - square_braces
+  - antlr_colon_semicolon
+keywords:
+  - import
+  - fragment
+  - lexer
+  - parser
+  - grammar
+  - returns
+  - locals
+  - throws
+  - catch
+  - finally
+  - mode
+  - tokens
+  - print
+  - read
+  - fold
+  - apply