Clarify that runtime support is optional.
Clarify that runtime support is optional.

xpol/luainstaller,keplerproject/luarocks,aryajur/luarocks,xpol/luavm,robooo/luarocks,xpol/luavm,lxbgit/luarocks,xpol/luavm,rrthomas/luarocks,luarocks/luarocks,coderstudy/luarocks,luarocks/luarocks,xiaq/luarocks,coderstudy/luarocks,tst2005/luarocks,xpol/luainstaller,starius/luarocks,xiaq/luarocks,aryajur/luarocks,ignacio/luarocks,lxbgit/luarocks,keplerproject/luarocks,xpol/luarocks,xpol/luainstaller,tarantool/luarocks,aryajur/luarocks,xpol/luarocks,luarocks/luarocks,tst2005/luarocks,xpol/luavm,tarantool/luarocks,rrthomas/luarocks,coderstudy/luarocks,ignacio/luarocks,rrthomas/luarocks,xpol/luavm,starius/luarocks,rrthomas/luarocks,starius/luarocks,tarantool/luarocks,usstwxy/luarocks,robooo/luarocks,usstwxy/luarocks,xpol/luarocks,keplerproject/luarocks,xiaq/luarocks,lxbgit/luarocks,ignacio/luarocks,starius/luarocks,aryajur/luarocks,tst2005/luarocks,xpol/luarocks,lxbgit/luarocks,coderstudy/luarocks,xpol/luainstaller,usstwxy/luarocks,xiaq/luarocks,tst2005/luarocks,ignacio/luarocks,usstwxy/luarocks,keplerproject/luarocks,robooo/luarocks,robooo/luarocks