Notable changes:

• We revert back prefixing v1 docs with v1_.
• Dangling _ suffix is removed, e.g. cloud_functions_ => cloud_functions
• Bunch more documents not in the ToC is created.
• Some odd file naming, e.g. config.config-1.html instead of config.config1.html
• Some type definiitions moved under common/ directory and hence the filename changed, e.g. providers_https is now common_providers_https.
• Added more pages to provders.https namesapce (CallbleRequest, AppCheckData, AuthData).