dev: ignore dev certs folder (#118)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

* **Documentation**
* Added setup guide for local development with certificate generation
instructions.

* **Chores**
* Updated configuration to exclude certificate files from version
control.
  * Removed certificate files from repository.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: NicolasCARPi

.gitignore

@@ -14,3 +14,6 @@ cli
 # Air live reload
 tmp/
 build-errors.log
+
+# dev
+nginx/certs

nginx/README.md

@@ -1,3 +1,15 @@
 # nginx folder
 
 For local reverse proxy in dev.
+
+## certs
+
+Generate the certs with `mkcert`: https://github.com/filosottile/mkcert
+
+~~~bash
+mkdir certs
+cd certs
+mkcert eln.community.local
+mv eln.community.local.pem server.crt
+mv eln.community.local-key.pem server.key
+~~~