docs: update TLS example to quote strings not spawn a subshell
@@ -25,8 +25,8 @@ If you run Docker locally, you can then use
```
$ docker run ... \
- -e SERVE_TLS_CERT_BASE64=$(SERVE_TLS_CERT_BASE64) \
- -e SERVE_TLS_KEY_BASE64=$(SERVE_TLS_KEY_BASE64) \
+ -e SERVE_TLS_CERT_BASE64="$SERVE_TLS_CERT_BASE64" \
+ -e SERVE_TLS_KEY_BASE64="$SERVE_TLS_KEY_BASE64" \
...
```
