api docs: Fix link to client libraries.
api docs: Fix link to client libraries.

This should have been caught by CI.

brainwane/zulip,hackerkid/zulip,showell/zulip,synicalsyntax/zulip,showell/zulip,hackerkid/zulip,timabbott/zulip,rht/zulip,andersk/zulip,timabbott/zulip,eeshangarg/zulip,eeshangarg/zulip,zulip/zulip,andersk/zulip,hackerkid/zulip,kou/zulip,punchagan/zulip,punchagan/zulip,timabbott/zulip,synicalsyntax/zulip,punchagan/zulip,kou/zulip,kou/zulip,hackerkid/zulip,synicalsyntax/zulip,showell/zulip,synicalsyntax/zulip,shubhamdhama/zulip,showell/zulip,brainwane/zulip,rht/zulip,timabbott/zulip,timabbott/zulip,kou/zulip,shubhamdhama/zulip,brainwane/zulip,brainwane/zulip,rht/zulip,andersk/zulip,brainwane/zulip,andersk/zulip,zulip/zulip,shubhamdhama/zulip,rht/zulip,rht/zulip,andersk/zulip,eeshangarg/zulip,showell/zulip,timabbott/zulip,synicalsyntax/zulip,timabbott/zulip,zulip/zulip,punchagan/zulip,shubhamdhama/zulip,eeshangarg/zulip,zulip/zulip,zulip/zulip,shubhamdhama/zulip,shubhamdhama/zulip,synicalsyntax/zulip,synicalsyntax/zulip,eeshangarg/zulip,kou/zulip,hackerkid/zulip,kou/zulip,punchagan/zulip,brainwane/zulip,kou/zulip,rht/zulip,eeshangarg/zulip,andersk/zulip,hackerkid/zulip,eeshangarg/zulip,showell/zulip,punchagan/zulip,andersk/zulip,zulip/zulip,showell/zulip,brainwane/zulip,rht/zulip,zulip/zulip,shubhamdhama/zulip,punchagan/zulip,hackerkid/zulip