net.html: add note to parse and parse_file, that they will produce a DOM with lowercased tag names (#19720)

vlib/net/html/html.v

@@ -3,6 +3,8 @@ module html
 import os
 
 // parse parses and returns the DOM from the given text.
+// Note: this function will parse all tags to lowercase.
+// E.g. <MyTag>content<MyTag/> is converted to <mytag>content<mytag>
 pub fn parse(text string) DocumentObjectModel {
 	mut parser := Parser{}
 	parser.parse_html(text)
@@ -10,6 +12,8 @@ pub fn parse(text string) DocumentObjectModel {
 }
 
 // parse_file parses and returns the DOM from the contents of a file.
+// Note: this function will parse all tags to lowercase.
+// E.g. <MyTag>content<MyTag/> is converted to <mytag>content<mytag>
 pub fn parse_file(filename string) DocumentObjectModel {
 	content := os.read_file(filename) or { return DocumentObjectModel{
 		root: &Tag{}