I've just committed and pushed some new #BSSG features and fixes:

- Re-implement `--config <path>` command-line flag for `bssg.sh`. This allows specifying a custom configuration file (e.g., a site's `config.sh.local`) to override default settings and the standard `config.sh.local` in the BSSG core directory. Useful for managing multiple sites or running commands from the core directory against a specific site context.
- Add support for `BSSG_LCONF` environment variable. If set to a valid configuration file path, it will be used when `--config` is not specified, providing an alternative way to set the site context for a session.
- Add `CACHE_DIR` configuration variable (`config.sh`, default `.bssg_cache`). Allows specifying a custom location for the build cache.
- New configuration option `ARCHIVES_LIST_ALL_POSTS` (in `config.sh`, default `false`). If set to `true`, the main `archives/index.html` page will list all posts chronologically under their respective month links, in addition to the standard year/month navigation.

- The `init` script now adds a `CACHE_DIR` setting to the new site's `config.sh.local`, pointing to `.bssg_cache` within the site's directory (e.g., `/path/to/site/.bssg_cache`). This ensures separate caches for initialized sites.
- Change default answer to 'Yes' (Y) in the `init` script when asking whether to modify the core `config.sh.local` to automatically source the new site's configuration.