Fix broken documentation links

[mattdot]

This pull request primarily updates the URLs of various documentation references across multiple files. The changes remove the language-specific segment (/en-us/) from the URLs, making them default to the user's browser language settings. Additionally, a minor change is made to the docs/data-sources/currencies.md file, updating the use_client attribute to use_cli. Fixes #314

URL updates:

• .devcontainer/features/pac/devcontainer-feature.json: Updated the documentationURL attribute.
• docs/data-sources/billing_policies.md: Updated several URLs in the file. [1] [2]
• docs/data-sources/billing_policies_environments.md: Updated several URLs in the file.
• docs/data-sources/connectors.md: Updated several URLs in the file. [1] [2]
• docs/data-sources/currencies.md: Updated several URLs in the file. [1] [2]
• docs/data-sources/data_loss_prevention_policies.md: Updated the URL in the file.
• docs/data-sources/environment_application_packages.md: Updated several URLs in the file.
• docs/data-sources/environment_powerapps.md: Updated the URL in the file.
• docs/data-sources/environment_settings.md: Updated several URLs in the file. [1] [2] [3] [4]
• docs/data-sources/environments.md: Updated the URL in the file.
• docs/data-sources/languages.md: Updated the URL in the file. (Fc34222L3R3)
• docs/data-sources/locations.md: Updated the URL in the file.

Other changes:

• docs/data-sources/currencies.md: Changed the use_client attribute to use_cli.