Mention HTTPS needed for Chrome

README.md

@@ -37,6 +37,12 @@ docker run -d --name bitwarden -v /bw-data/:/data/ -p 80:80 mprasil/bitwarden:la
 ```
 This will preserve any persistent data under /bw-data/, you can adapt the path to whatever suits you.
 
+**IMPORTANT**: Some web browsers, like Chrome, disallow the use of Web Crypto APIs in insecure contexts. In this case, you might get an error like `Cannot read property 'importKey'`. To solve this problem, you need to access the web vault from HTTPS. 
+
+This can be configured in [bitwarden_rs directly](https://github.com/dani-garcia/bitwarden_rs/wiki/Enabling-HTTPS) or using a third-party reverse proxy ([some examples](https://github.com/dani-garcia/bitwarden_rs/wiki/Proxy-examples)).
+
+If you have an available domain name, you can get HTTPS certificates with [Let's Encrypt](https://letsencrypt.org/), or you can generate self-signed certificates with utilities like [mkcert](https://github.com/FiloSottile/mkcert). Some proxies automatically do this step, like Caddy (see examples linked above).
+
 ## Usage
 See the [bitwarden_rs wiki](https://github.com/dani-garcia/bitwarden_rs/wiki) for more information on how to configure and run the bitwarden_rs server.