Add options to disable groups of key mappings

[NI57721]

I added options to disable groups of key mappings partially .
The groups are categorized in accordance with the description in AZIK.

g:skkeleton_azik_disable_rule_N corresponds to 入力方法（そのN） in the web site above.

let g:skkeleton_azik_disable_rule_1 = v:false
let g:skkeleton_azik_disable_rule_2 = v:false
let g:skkeleton_azik_disable_rule_3 = v:false
let g:skkeleton_azik_disable_rule_4 = v:false

[shg-eo]

Thank you for your commits. But it is hard to take the time to commit them because I'm so busy.
I'll check them slowly, sorry.

[NI57721]

Don't worry about it. I'll wait for you.