feat(ziggy-schema): Add ziggy-schema parser and queries

Ziggy-schema is the schema definition file format for a ziggy file.

queries/ziggy_schema/highlights.scm

@@ -0,0 +1,38 @@
+(struct_field
+  key: (_) @keyword)
+
+(tag_name) @function
+
+[
+  "unknown"
+  "any"
+  "struct"
+  "root"
+  "enum"
+  "map"
+] @keyword
+
+(identifier) @type
+
+"?" @type
+
+[
+  "bool"
+  "bytes"
+  "int"
+  "float"
+] @constant.builtin
+
+(doc_comment) @comment.documentation
+
+[
+  ","
+  "|"
+] @punctuation.delimiter
+
+[
+  "["
+  "]"
+  "{"
+  "}"
+] @punctuation.bracket

queries/ziggy_schema/indents.scm

@@ -0,0 +1,3 @@
+(struct) @indent.begin
+
+"}" @indent.end