feat(layout): add kenshin 剣心 (@inscapist)

[inscapist]

Description

Adds kenshin layout featuring

• same hand h/j/k/l
• high inrolls
• low scissors
• high alternation
• unchanged c positions compared to qwerty
• alt-able sy, sg, cy with LM and LI fingers
• alt-able ph with RI and RM fingers
• sc sfbs can be an effortless downward motion due to angle mod

In short, all (top 10) sfbs are either altable or slidable, and all adjacent to each other

Top 10 SFBS according to shai

sc    0.115%
ui    0.104%
ys    0.103%
rl    0.074%
oa    0.072%
gs    0.059%
ph    0.058%
sy    0.043%
ws    0.041%
cy    0.030%

Angle-modded for row staggered keyboards.

  ; u o w q  b k m l j
  e i a s y  p h t r n
   . ' c g /  f d z x v

SHAI:
  Alt: 32.22%
  Rol: 41.68%   (In/Out: 26.18% | 15.50%)
  One:  1.62%   (In/Out:  0.45% |  1.17%)
  Rtl: 43.30%   (In/Out: 26.62% | 16.68%)
  Red:  3.84%   (Bad:     0.15%)

  SFB: 1.12%
  SFS: 4.71%    (Red/Alt: 1.54% | 3.17%)

  LH/RH: 54.82% | 45.18%

[inscapist]

noticed some issue with the k letter position. Closed until its fixed!