Add Helm extension (#746)

![Screenshot 2024-05-17 at 3 50
00 PM](https://github.com/zed-industries/extensions/assets/775203/fa661452-332d-4555-80eb-bcd27b81c362)

I've got this extension to a point now where all highlights seem to be
working properly, but there are still a couple issues I need some help
with:
- Files aren't automatically detected as "Helm", but instead as "YAML",
need to find a way to detect helm if the `*.yaml` file is located in a
directory named `templates`: `templates/*.yaml`, is this possible?
- Some errors are being displayed as YAML errors, but really its valid
Helm syntax

![Screenshot 2024-05-17 at 3 53
37 PM](https://github.com/zed-industries/extensions/assets/775203/6aa09c4b-e562-413c-b5f9-1426a8ca9a98)

---------

Co-authored-by: Peter Tripp <[email protected]>
Co-authored-by: Marshall Bowers <[email protected]>

.gitmodules

@@ -502,6 +502,10 @@
 	path = extensions/harper
 	url = https://github.com/Stef16Robbe/harper_zed.git
 
+[submodule "extensions/helm"]
+	path = extensions/helm
+	url = https://github.com/cabrinha/helm.zed.git
+
 [submodule "extensions/hex-light-theme"]
 	path = extensions/hex-light-theme
 	url = https://github.com/coghost/light-zed-theme

extensions.toml

@@ -558,6 +558,10 @@ submodule = "extensions/zed"
 path = "extensions/haskell"
 version = "0.1.1"
 
+[helm]
+submodule = "extensions/helm"
+version = "0.0.1"
+
 [hex-light-theme]
 submodule = "extensions/hex-light-theme"
 version = "0.0.3"