Take language code from filename instead of .yml files

[Pure-Peace]

Before

en: # The language code of this mapping file
  hello: Hello world # A simple key -> value mapping
  messages:
    hello: Hello, %{name} # A nested key.sub_key -> value mapping, in this case "messages.hello" maps to "Hello, %{name}"

After that, there is no need to add a first-level language code to the .yml file

hello: Hello world # A simple key -> value mapping
messages:
  hello: Hello, %{name} # A nested key.sub_key -> value mapping, in this case "messages.hello" maps to "Hello, %{name}"

This modification makes the locales .yml file more standardized, and some vscode plugins can be used directly, such as i18n-ally

.vscode/i18n-ally-custom-framework.yml

languageIds:
  - rust

usageMatchRegex:
  - "[^\\w\\d]t!\\(['\"]({key})['\"]"

monopoly: true

Work for rust now!