help: Add a bottom border in section headings.
help: Add a bottom border in section headings.

This commit adds a bottom border to all the section
headings.

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