Update the project

Rename a file, README.txt -> hogehoge.txt. And sample.txt is added.
Modify hogehoge.txt

Add a new line.
Modify hogehoge.txt

Add !!mark.
Modify sample.txt

Add "Topic B" to the 5th line.
Modify sample.txt

Add comment.
Modify sample.txt

Replace CCCCC with BBBBB.
Merge branch 'topicBB' into topicB
Merge branches 'topicA' and 'topicB'
Modify .gitignore

Ignore .patch files.
Revert "Modify .gitignore"

This reverts commit 251232ac16638b47703d81e8099ed4680ccf2b23.