doc: use "Groonga" notation
doc: use "Groonga" notation
doc: use "Groonga" notation
doc: remove trailing spaces
Merge pull request #129 from cosmo0920/use-Groonga-notation-index

doc: use "Groonga" notation related to index.txt and .po

Patch by cosmo. Thanks!!!
Merge pull request #130 from cosmo0920/use-Groonga-notation-lexicon

doc: use "Groonga" notation related to lexicon.txt and .po

Patch by cosmo. Thanks!!!
Merge pull request #131 from cosmo0920/use-Groonga-notation-match_columns

doc: use "Groonga" notation related to match_columns.txt and po

Patch by cosmo. Thanks!!!
doc ja: remove obsolete messages