chore: Extract languages from zed crate (#8270)

- Moves languages module from `zed` into a separate crate. That way we
have less of a long pole at the end of compilation.
- Removes moot dependencies on editor/picker. This is totally harmless
and might help in the future if we decide to decouple picker from
editor.

Before:
```
Number of crates that depend on 'picker' but not on 'editor': 1
Total number of crates that depend on 'picker': 13
Total number of crates that depend on 'editor': 30
```
After:
```
Number of crates that depend on 'picker' but not on 'editor': 5
Total number of crates that depend on 'picker': 12
Total number of crates that depend on 'editor': 26
```
The more crates depend on just picker but not editor, the better in that
case.

Release Notes:

- N/A

crates/languages/src/dockerfile/highlights.scm

@@ -0,0 +1,63 @@
+; Dockerfile instructions set taken from:
+; https://docs.docker.com/engine/reference/builder/#overview
+; https://github.com/helix-editor/helix/blob/78c34194b5c83beb26ca04f12bf9d53fd5aba801/runtime/queries/dockerfile/highlights.scm
+[
+	"ADD"
+	"ARG"
+	"CMD"
+	"COPY"
+	"ENTRYPOINT"
+	"ENV"
+	"EXPOSE"
+	"FROM"
+	"HEALTHCHECK"
+	"LABEL"
+	"MAINTAINER"
+	"ONBUILD"
+	"RUN"
+	"SHELL"
+	"STOPSIGNAL"
+	"USER"
+	"VOLUME"
+	"WORKDIR"
+
+	; "as" for multi-stage builds
+	"AS"
+] @keyword
+
+[
+	":"
+	"@"
+] @operator
+
+(comment) @comment
+
+(image_spec
+	(image_tag
+		":" @punctuation.special)
+	(image_digest
+		"@" @punctuation.special))
+
+[
+  (double_quoted_string)
+  (single_quoted_string)
+  (json_string)
+] @string
+
+[
+  (env_pair)
+  (label_pair)
+] @constant
+
+[
+  (param)
+  (mount_param)
+] @function
+
+(expansion
+    [
+        "$"
+        "{"
+        "}"
+    ] @punctuation.special
+) @constant