Add info about `make doc` and make install.sh executable.
|@@ -16,7 +16,7 @@ make install|
|That will make a 'git subtree' (note: space instead of dash) command|
|available. See the file git-subtree.txt for more.|
|-You can also install the man page by doing:|
|+You can also install the man page by doing (requires asciidoc):|
|cp git-subtree.1 /usr/share/man/man1/|