feat: add network configuration table (gnolang#1707)

<!-- please provide a detailed description of the changes made in this
pull request. -->
This PR introduces network configurations to the RPC endpoints page
within our
[documentation](https://docs.gno.land/reference/rpc-endpoints).

Closes: gnolang#1706 

<details><summary>Contributors' checklist...</summary>

- [ ] Added new tests, or not needed, or not feasible
- [ ] Provided an example (e.g. screenshot) to aid review or the PR is
self-explanatory
- [x] Updated the official documentation or not needed
- [ ] No breaking changes were made, or a `BREAKING CHANGE: xxx` message
was included in the description
- [x] Added references to related issues and PRs
- [ ] Provided any useful hints for running manual tests
- [ ] Added new benchmarks to [generated
graphs](https://gnoland.github.io/benchmarks), if any. More info
[here](https://github.com/gnolang/gno/blob/master/.benchmarks/README.md).
</details>

docs/reference/rpc-endpoints.md

@@ -4,6 +4,19 @@ id: rpc-endpoints
 
 # Gno RPC Endpoints
 
+## Network Configurations
+
+This is a list of Gno.land networks. Use the information below to configure wallets and Web3 middleware providers to the appropriate RPC Server Address and Chain ID to connect to the correct Gno network.
+
+Note: The below endpoints may produce errors on dialing if the ports are not provided (eg, `:443`).
+
+| Network     | RPC Server Addr.               | Chain ID      |
+| ----------- | ------------------------------ | ------------- |
+| Portal Loop | https://rpc.gno.land:443       | `portal-loop` |
+| Testnet 3   | https://rpc.test3.gno.land:443 | `test3`       |
+| Staging     | http://staging.gno.land:36657  | `test3`       |
+| Local       | http://127.0.0.1:26657         | `dev`         |
+
 ## Common Parameters
 
 #### Response