Is it possible to create an alias/shortcut/makro/function for a collection of keywords?
You can tell the tool, in this case SQL Developer, to do it for you.

I talk about how to set this up here
 https://www.thatjeffsmith.com/archive/2014/02/auto-replace-in-oracle-sql-developer/

But basically, you define a code template in the preferences with the code you want to be recognized as a template, and then the code you want inserted.

If there is only one match for your template, when you invoke it with ctrl+spacebar, it automatically inserts the code.

If there are multiple matches, it prompts you for what you want. 

I built two, one for 


auto_increment - long form
autoincrement - short form




You could of course submit an enhancement request for the database so this keyword would be honored, but that's a years long process, assuming it even gets accepted and implemented.