webhooks/appfollow: Reformat documentation steps into numbered list.
webhooks/appfollow: Reformat documentation steps into numbered list.

This is a part of our efforts to migrate our webhook docs to have
a more structured numbered-list format similar to our /help docs.

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