Minor change to install.md

docs/install.md

@@ -248,9 +248,9 @@ To run nexush for Mac/arm64 with user admin@nexus.org:
 ./build/arm64/darwin/nexush admin@nexus.org
 ```
 
-To run nexus-cli for Linux/i386 with user janedoe@nexus.org:
+To run nexus-cli for Linux/i386 with user janedoe@nexus.org and with an external public certificate (i.e. not embedded):
 ```sh
-./build/386/linux/nexus-cli janedoe@nexus.org
+NEXUS_CERT=/tmp/ca-cert.pem ./build/386/linux/nexus-cli janedoe@nexus.org
 ```
 
 ## Building nexus-exam and running it