[ci skip] Updated create! documentation description and added +attributes+ for rdoc
Merge pull request #16384 from tomkadwill/improved_create_documentation

[ci skip] Added +object+ and +attributes+ to create! description for rdoc
Rephrase how we explain RecordInvalid exception in the context of
`#create!` regarding validations in contrast to the behavior of
`#create`. Also describe creating multiple objects using an array of
hashes as the +attributes+ parameter. [ci skip] /cc #16384