file_icons: Add icon key for Crystal and ECR files (#24903)

Release Notes:

- Icon themes: Added the ability to change the file icon for Crystal
(`.cr`, `.ecr`) files.

---------

Co-authored-by: Marshall Bowers <git@maxdeviant.com>

assets/icons/file_icons/file_types.json

@@ -29,6 +29,7 @@
     "conf": "settings",
     "cpp": "cpp",
     "cs": "csharp",
+    "cr": "crystal",
     "css": "css",
     "csv": "storage",
     "cxx": "cpp",
@@ -43,6 +44,7 @@
     "dll": "storage",
     "doc": "document",
     "docx": "document",
+    "ecr": "crystal",
     "eex": "elixir",
     "elm": "elm",
     "erl": "erlang",

crates/theme/src/icon_theme.rs

@@ -67,6 +67,7 @@ const FILE_ICONS: &[(&str, &str)] = &[
     ("code", "icons/file_icons/code.svg"),
     ("coffeescript", "icons/file_icons/coffeescript.svg"),
     ("cpp", "icons/file_icons/cpp.svg"),
+    ("crystal", "icons/file_icons/file.svg"),
     ("csharp", "icons/file_icons/file.svg"),
     ("css", "icons/file_icons/css.svg"),
     ("cue", "icons/file_icons/file.svg"),