Add another sentence to the legal section
Change table structure to match others

While I was working on the Debian package, I looked up the Debian
package names in the second column of the dependencies. However, when I
did the optional dependencies, I used the second column, which is the
program name.

Therefore, I matched the column order of the last table with the other
two tables.
Write about GitHub page in README
Fix syntax
Table of contents
Table of contents
Add another dependency for qt4-default