changed the config paths to $lightning-dir/config or /networkname/config
plugins are downloaded to the SDcard:
/home/bitcoin/cln-plugins-available/
symlinked and loaded automatically from:
/home/bitcoin/${netprefix}cln-plugins-enabled
Related: #2295
similar to the nginx model make 2 directories for plugins:
cln-plugins-enabled - symlinked to ~/.lightning/plugins
plugins from here are loaded automatically on cln start
cln-plugins-available: plugins are downloaded here to
be run until the next cln restart (or stopped with runonce)
note the disk is mounted with noexec so plugins can't
run from there
discuss in: https://github.com/rootzoll/raspiblitz/issues/2295
