Add syntax highlighting for .htm and .shtml files (#6705)

enabled syntax highlighting for **.htm** and **.shtml** files

Release Notes:
- Added support for syntax highlighting in HTML files with `.htm` and
`.shtml` extensions
([#4510](https://github.com/zed-industries/zed/issues/4510)).

crates/zed/src/languages/html/config.toml

@@ -1,5 +1,5 @@
 name = "HTML"
-path_suffixes = ["html"]
+path_suffixes = ["html", "htm", "shtml"]
 autoclose_before = ">})"
 block_comment = ["<!-- ", " -->"]
 brackets = [