docs: Fix typo in emoji.md.
docs: Fix typo in emoji.md.

Change emoji-map.json to emoji_map.json.

zulip/zulip,kou/zulip,hackerkid/zulip,eeshangarg/zulip,andersk/zulip,punchagan/zulip,kou/zulip,rht/zulip,kou/zulip,punchagan/zulip,andersk/zulip,eeshangarg/zulip,punchagan/zulip,hackerkid/zulip,eeshangarg/zulip,hackerkid/zulip,kou/zulip,punchagan/zulip,hackerkid/zulip,punchagan/zulip,kou/zulip,eeshangarg/zulip,hackerkid/zulip,punchagan/zulip,andersk/zulip,eeshangarg/zulip,andersk/zulip,eeshangarg/zulip,rht/zulip,kou/zulip,rht/zulip,andersk/zulip,hackerkid/zulip,andersk/zulip,zulip/zulip,zulip/zulip,rht/zulip,zulip/zulip,kou/zulip,andersk/zulip,rht/zulip,zulip/zulip,zulip/zulip,eeshangarg/zulip,rht/zulip,hackerkid/zulip,punchagan/zulip,rht/zulip,zulip/zulip