Added a file for mapping emails to persons in Git.

https://developer.atlassian.com/blog/2017/06/aliasing-authors-in-git/

$ git summary

 project  : ogs
 repo age : 8 years
 active   : 1859 days
 commits  : 12781
 files    : 4757
 authors  :
  3162	Dmitri Naumov      24.7%
  2755	Thomas Fischer     21.6%
  2498	Lars Bilke         19.5%
  1317	Karsten Rink       10.3%
  1095	Christoph Lehmann  8.6%
  1045	Norihiro Watanabe  8.2%
   711	Wenqing Wang       5.6%
    60	Yonghui Huang      0.5%
    21	Francesco Parisio  0.2%
    19	Renchao Lu         0.1%
    19	Chaofan Chen       0.1%
    17	Jasper Bathmann    0.1%
    16	Xing-Yuan Miao     0.1%
    10	Keita Yoshioka     0.1%
     9	Haibing Shao       0.1%
     7	Marc Walther       0.1%
     6	Tianyuan Zheng     0.0%
     5	OGS Bot            0.0%
     3	Jan Thiedau        0.0%
     2	Norbert Grunwald   0.0%
     2	Carolin Helbig     0.0%
     1	Thomas Nagel       0.0%
     1	Myles English      0.0%