[bn] Add initial Bengali localization

[debjotyms]

This PR introduces Bengali (bn) as a new language for the Helm documentation. The following changes have been made:

1. Content Directory:

   • Added a new content/bn directory to house Bengali translations.
   • Created an initial landing page (_index.md) for the Bengali documentation.

2. i18n Configuration:

   • Added a bn.toml file in the i18n directory to manage Bengali translations for website phrases.
   • Translated key phrases into Bengali based on the English template.

3. Global Configuration:

   • Updated the config.toml file to include Bengali as a supported language with the appropriate settings:
     • Language code: bn
     • Language name: বাংলা Bengali
     • Content directory: content/bn

4. Translated Content:

   • Added an initial translated version of the installation page (install.md) under content/bn/docs/intro.

5. Testing:

   • Verified the changes locally using the Hugo server to ensure the Bengali content renders correctly.
   • Ensured all internal links and navigation work as expected.

This is an initial step toward full Bengali localization. Future contributions will expand the translations to cover more sections of the documentation.

Signed-off-by: Debjoty Mitra [email protected]