Update README to mention autogen.sh
The top level README file in Tor's source code repo says:
`To build Tor from [`](`)
` ./configure && make && make install`
These instructions are outdated and do not work on the current repo (the configure script does not exist). The instructions should instead say:
`To build Tor from [`](`)
` ./autogen.sh && make && make install`
**Trac**:
**Username**: bestchai
issue