Docs: improvement for #2103 & #1795 (#2225)

This adds a bit of info on required command permissions to connect.

Author: NickCraver

docs/Configuration.md

@@ -170,6 +170,27 @@ The above is equivalent to (in the connection string):
 $INFO=,$SELECT=use
 ```
 
+Redis Server Permissions
+---
+If the user you're connecting to Redis with is limited, it still needs to have certain commands enabled for the StackExchange.Redis to succeed in connecting. The client uses:
+- `AUTH` to authenticate
+- `CLIENT` to set the client name
+- `INFO` to understand server topology/settings
+- `ECHO` for heartbeat. 
+- (Optional) `SUBSCRIBE` to observe change events
+- (Optional) `CONFIG` to get/understand settings
+- (Optional) `CLUSTER` to get cluster nodes
+- (Optional) `SENTINEL` only for Sentinel servers
+- (Optional) `GET` to determine tie breakers
+- (Optional) `SET` (_only_ if `INFO` is disabled) to see if we're writable
+ 
+For example, a common _very_ minimal configuration ACL on the server (non-cluster) would be:
+```bash
+-@all +@pubsub +@read +echo +info
+```
+
+Note that if you choose to disable access to the above commands, it needs to be done via the `CommandMap` and not only the ACL on the server (otherwise we'll attempt the command and fail the handshake). Also, if any of the these commands are disabled, some functionality may be diminished or broken.
+
 twemproxy
 ---
 

docs/Server.md

@@ -13,7 +13,7 @@ There are multiple ways of running redis on windows:
 
 - [Memurai](https://www.memurai.com/) : a fully supported, well-maintained port of redis for Windows (this is a commercial product, with a free developer version available, and free trials)
   - previous to Memurai, MSOpenTech had a Windows port of linux, but this is no longer maintained and is now very out of date; it is not recommended, but: [here](https://www.nuget.org/packages/redis-64/)
-- WSL/WSL2 : on Windows 10, you can run redis for linux in the Windows Subsystem for Linux; note, however, that WSL may have some significant performance implications, and WSL2 appears as a *different* machine (not the local machine), due to running as a VM
+- WSL/WSL2 : on Windows 10+, you can run redis for linux in the Windows Subsystem for Linux; note, however, that WSL may have some significant performance implications, and WSL2 appears as a *different* machine (not the local machine), due to running as a VM
 
 ## Docker