doc CSS hack: make anchors offset by header height
doc CSS hack: make anchors offset by header height

Using intra-page anchor links with the documentation prior to this
commit was sort of clumsy, since the sticky/floating header at the top
of the viewport would obscure about the topmost ~85 pixels of whatever
the link jumped to -- usually the section header and an initial
sentence or two.

This CSS hack makes anchor links jump about 88 pixels too high to
compensate for the height of the floating/sticky header.

tomersagi/titan,wangbf/titan,ThiagoGarciaAlves/titan,jankotek/titan,dylanht/titan,fengshao0907/titan,kalatestimine/titan,englishtown/titan,CYPP/titan,samanalysis/titan,kangkot/titan,ThiagoGarciaAlves/titan,jankotek/titan,nvoron23/titan,anuragkh/titan,pluradj/titan,jamestyack/titan,xlcupid/titan,hortonworks/titan,xlcupid/titan,mbrukman/titan,mbrukman/titan,amcp/titan,elubow/titan,amcp/titan,kangkot/titan,anuragkh/titan,graben1437/titan,jankotek/titan,pluradj/titan,hortonworks/titan,englishtown/titan,tomersagi/titan,wangbf/titan,thinkaurelius/titan,anuragkh/titan,graben1437/titan,mwpnava/titan,evanv/titan,fengshao0907/titan,jamestyack/titan,hortonworks/titan,anuragkh/titan,elkingtonmcb/titan,dylanht/titan,elubow/titan,elkingtonmcb/titan,qiuqiyuan/titan,ThiagoGarciaAlves/titan,englishtown/titan,tomersagi/titan,banjiewen/titan,elkingtonmcb/titan,tomersagi/titan,hortonworks/titan,thinkaurelius/titan,elubow/titan,jamestyack/titan,kalatestimine/titan,CYPP/titan,evanv/titan,jankotek/titan,kalatestimine/titan,samanalysis/titan,banjiewen/titan,fengshao0907/titan,thinkaurelius/titan,jamestyack/titan,ThiagoGarciaAlves/titan,jankotek/titan,banjiewen/titan,qiuqiyuan/titan,thinkaurelius/titan,kangkot/titan,fengshao0907/titan,kangkot/titan,amcp/titan,mwpnava/titan,wangbf/titan,englishtown/titan,evanv/titan,qiuqiyuan/titan,mwpnava/titan,mbrukman/titan,evanv/titan,wangbf/titan,samanalysis/titan,qiuqiyuan/titan,graben1437/titan,xlcupid/titan,elkingtonmcb/titan,tomersagi/titan,wangbf/titan,dylanht/titan,fengshao0907/titan,mbrukman/titan,CYPP/titan,xlcupid/titan,elkingtonmcb/titan,CYPP/titan,nvoron23/titan,anuragkh/titan,kangkot/titan,pluradj/titan,xlcupid/titan,jamestyack/titan,samanalysis/titan,amcp/titan,pluradj/titan,nvoron23/titan,hortonworks/titan,dylanht/titan,mwpnava/titan,evanv/titan,elubow/titan,nvoron23/titan,ThiagoGarciaAlves/titan,kalatestimine/titan,mbrukman/titan,kalatestimine/titan,banjiewen/titan,graben1437/titan,qiuqiyuan/titan,mwpnava/titan