feat: add develoeprs conferences agenda github repository (#51)

Author: scraly

README.md

@@ -166,6 +166,7 @@ Community-sourced tools for the DevRel industry. Brought to you by [The DevRel C
 * [SeeCFP](https://seecfp.com/): CFP list and email notification.
 * [Tech Daily CFP](https://mailchi.mp/f2e4ba861211/techdailycfp): Sends a daily newsletter of CFPs.
 * [Tulu.la](https://tulu.la) - Curated list of tech events and open CFPs. Friendly community and speaker support champions. Community-driven.
+* [Developers Conferences Agenda/list](https://github.com/scraly/developers-conferences-agenda/) - A list of worldwide conferences since 2017 with date and location
 
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