[IBL] instructions for handling Ohtani injuries

[Sean Sweda]

Ohtani has separate injury/durability ratings for the batter & pitcher  
card.  This blog post explains how to handle an injury:

http://www.ibl.org/~sweda/2019/03/rules-for-shohei-ohtani/

I also updated our wiki with injury reporting examples (bottom of page):
http://wiki.ibl.org/dokuwiki/doku.php/users:grs_instructions

The usage system was overhauled to handle players who need to have both  
batter and pitcher usage tracked.  Ohtani will receive injury credit for  
both batter and pitcher usage from standard injuries that prevent him from  
playing in any capacity.  He will receive pitcher usage injury credit only  
for the time that he's not allowed to pitch but may still bat.

Sean