fix(syntaxes): python multiline f strings support

Fix #69

Author: barklan

syntaxes/highlight-sql-string.json

@@ -109,7 +109,8 @@
             ]
         },
         {
-            "begin": "(\"\"\")(--\\s*sql)",
+            "comment": "Python multi-line strings",
+            "begin": "f?(\"\"\")(--\\s*sql)",
             "beginCaptures": {
                 "2": {
                     "name": "comment.sql"

test/testdata/multiline.py

@@ -9,3 +9,8 @@
 query_with_db_identifiers = """--sql
     delete * from "book";
 """
+
+some_table = "book"
+f_string = f"""--sql
+select * from {some_table}
+"""