Add to wiki: Install from source

[xet7]

Add to wiki, how to install standalone version of Wefork from source.

There is some of previous info at: https://github.com/wefork/wekan/pull/20

Add:

• installing meteor, script at meteor website
• on Linux 32bit and 64bit, use n , sudo npm install -g n && n 0.10.48 . On other platforms, use nvm.
• after installing npm, update it: npm install -g npm

[xet7]

In progress: https://github.com/wefork/wekan/wiki/Install-from-source

[xet7]

Install from source works for me.