Add docs with up to date instructions on updating default similarity (#21242)
Add docs with up to date instructions on updating default similarity (#21242)

* Add docs with up to date instructions on updating default similarity

The default similarity can no longer be set in the configuration file
(you will get an error on startup). Update the docs with the method
that works.

* Add instructions for changing similarity on index creation

strapdata/elassandra5-rc,strapdata/elassandra5-rc,strapdata/elassandra5-rc,strapdata/elassandra5-rc,strapdata/elassandra5-rc