Rename "syntax" package to "lexers"

lexers/stxXml.go

@@ -0,0 +1,24 @@
+//go:build stxXml || stxAll
+
+package lexers
+
+func init() {
+	syntaxMap["xml"] = &lazySyntax{init: func() []byte {
+		return []byte(`filetype: xml
+rules:
+    - type: "(<(/)?[a-zA-Z:]+>)"
+    - type: "(<(/)?[a-zA-Z:]+[[:space:]]+)"
+    - constant.specialChar: '[a-zA-Z0-9]+="(.*)+"'
+    - statement: '([a-zA-Z0-9]+)='
+    - type: "(([[:space:]])?/?>([[:space:]]+)?$)"
+    - comment:
+        start: "<!DOCTYPE"
+        end: "[/]?>"
+        rules: []
+    - comment:
+        start: "<!--"
+        end: "-->"
+        rules: []
+    - special: "&[^;]*;"`)
+	}}
+}