Change sidebar headings in API docs to not have pointer cursor.
Change sidebar headings in API docs to not have pointer cursor.

Previosly, a pointer cursor would display when hovering over some of the
headings in the API docs, however nothing would happen when clicked.

Fixes #7702.

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