[ja] Translated some headings
[ja] Translated install.rst
Merge pull request #292 from inouet/patch-12

[ja] Translated install.rst
Translated "Caching Related Records Recursively"
Merge pull request #293 from JimmDiGrizli/patch-14

Translated "Caching Related Records Recursively"
first commit to polish documentation
Merge pull request #294 from tiraeth/polish

[WIP] Polish Documentation