/help/: Reduce margin-top for closer anchoring.
/help/: Reduce margin-top for closer anchoring.

This lowers the amount of margin in the :before hack that we use
to put padding before anchored elements from 40px to 30px on <h1>
tags and 10px on everything else, which seems to be plenty.

Fixes: #7069.

kou/zulip,brockwhittaker/zulip,jackrzhang/zulip,dhcrzf/zulip,mahim97/zulip,brainwane/zulip,tommyip/zulip,zulip/zulip,jackrzhang/zulip,hackerkid/zulip,kou/zulip,zulip/zulip,mahim97/zulip,andersk/zulip,andersk/zulip,brockwhittaker/zulip,dhcrzf/zulip,jackrzhang/zulip,kou/zulip,eeshangarg/zulip,zulip/zulip,timabbott/zulip,synicalsyntax/zulip,mahim97/zulip,shubhamdhama/zulip,hackerkid/zulip,mahim97/zulip,Galexrt/zulip,andersk/zulip,rht/zulip,brockwhittaker/zulip,rishig/zulip,dhcrzf/zulip,andersk/zulip,eeshangarg/zulip,tommyip/zulip,jackrzhang/zulip,rht/zulip,synicalsyntax/zulip,rht/zulip,Galexrt/zulip,andersk/zulip,brockwhittaker/zulip,dhcrzf/zulip,jackrzhang/zulip,punchagan/zulip,andersk/zulip,tommyip/zulip,rht/zulip,tommyip/zulip,synicalsyntax/zulip,kou/zulip,showell/zulip,timabbott/zulip,shubhamdhama/zulip,hackerkid/zulip,synicalsyntax/zulip,Galexrt/zulip,shubhamdhama/zulip,rishig/zulip,showell/zulip,brockwhittaker/zulip,brainwane/zulip,rishig/zulip,eeshangarg/zulip,hackerkid/zulip,hackerkid/zulip,kou/zulip,hackerkid/zulip,shubhamdhama/zulip,kou/zulip,punchagan/zulip,synicalsyntax/zulip,timabbott/zulip,tommyip/zulip,timabbott/zulip,showell/zulip,rishig/zulip,mahim97/zulip,rht/zulip,punchagan/zulip,eeshangarg/zulip,kou/zulip,rht/zulip,brockwhittaker/zulip,jackrzhang/zulip,brainwane/zulip,zulip/zulip,Galexrt/zulip,tommyip/zulip,zulip/zulip,brainwane/zulip,tommyip/zulip,showell/zulip,jackrzhang/zulip,shubhamdhama/zulip,showell/zulip,eeshangarg/zulip,eeshangarg/zulip,mahim97/zulip,hackerkid/zulip,synicalsyntax/zulip,shubhamdhama/zulip,eeshangarg/zulip,shubhamdhama/zulip,brainwane/zulip,showell/zulip,Galexrt/zulip,punchagan/zulip,zulip/zulip,rishig/zulip,punchagan/zulip,timabbott/zulip,rht/zulip,dhcrzf/zulip,brainwane/zulip,showell/zulip,timabbott/zulip,zulip/zulip,dhcrzf/zulip,dhcrzf/zulip,Galexrt/zulip,punchagan/zulip,rishig/zulip,rishig/zulip,synicalsyntax/zulip,andersk/zulip,brainwane/zulip,punchagan/zulip,Galexrt/zulip,timabbott/zulip