Add recommendations around language injection
Add recommendations around language injection

This is an enhancement of the section about IntelliJ IDEA's inspections.
Proper handling of language injection is unfortunately not automatic,
and there is no objective truth to how to do it. But since we're working
with SQL statements a lot, I find it useful.

electrum/presto,11xor6/presto,Praveen2112/presto,smartnews/presto,losipiuk/presto,dain/presto,11xor6/presto,electrum/presto,smartnews/presto,smartnews/presto,losipiuk/presto,ebyhr/presto,electrum/presto,electrum/presto,ebyhr/presto,electrum/presto,ebyhr/presto,dain/presto,11xor6/presto,dain/presto,losipiuk/presto,dain/presto,smartnews/presto,losipiuk/presto,dain/presto,Praveen2112/presto,Praveen2112/presto,11xor6/presto,Praveen2112/presto,11xor6/presto,ebyhr/presto,ebyhr/presto,Praveen2112/presto,smartnews/presto,losipiuk/presto