Rename "syntax" package to "lexers"

lexers/stxCaddyfile.go

@@ -0,0 +1,25 @@
+//go:build stxCaddyfile || stxAll
+
+package lexers
+
+func init() {
+	syntaxMap["caddyfile"] = &lazySyntax{init: func() []byte {
+		return []byte(`filetype: caddyfile
+rules:
+    - identifier: "^\\s*\\S+(\\s|$)"
+    - type: "^([\\w.:/-]+,? ?)+[,{]$"
+    - constant.specialChar: "\\s{$"
+    - constant.specialChar: "^\\s*}$"
+    - constant.string:
+        start: "\""
+        end: "\""
+        skip: "\\\\."
+        rules:
+            - constant.specialChar: "\\\\."
+    - preproc: "\\{(\\w+|\\$\\w+|%\\w+%)\\}"
+    - comment:
+        start: "#"
+        end: "$"
+        rules: []`)
+	}}
+}