Add paragraph to description and related objects

And fix bug: extract related-objects information from index file
Status Job ID Name Coverage
  Test
canceled #27495
stretch debian x86_64
debian_stretch_x86_64_deb

canceled #27497
dmg v10.11 osx
osx_10.11_x86_64_dmg

canceled #27498
dmg v10.8 osx
osx_10.8_x86_64_dmg

canceled #27500
stretch arm raspbian
raspbian_stretch_armv7l_deb

canceled #27496
x86_64 v16.04 ubuntu
ubuntu_16.04_x86_64_deb

canceled #27499
i386 windows
windows_i386_innosetup