Add protocol version documentation

.gitignore

@@ -4,3 +4,4 @@
 
 # Test server
 /mcserver
+/bettermc

docs/protocol-version.md

@@ -0,0 +1,39 @@
+# Protocol version
+
+The Minecraft protocol uses a version number to distinguish between different
+protocol versions. Each new Minecraft version having a change in its protocol
+gets a new protocol version.
+
+## List of versions
+
+- https://wiki.vg/Protocol_version_numbers#Versions_after_the_Netty_rewrite
+
+## Configuration
+
+In `lazymc` you may configure what protocol version to use:
+
+[`lazymc.toml`](../res/lazymc.toml):
+
+```bash
+# -- snip --
+
+[public]
+# Server version & protocol hint.
+# Sent to clients until actual server version is known.
+# See: https://git.io/J1Fvx
+version = "1.17.1"
+protocol = 756
+
+# -- snip --
+```
+
+It is highly recommended to set these to match that of your server version to
+allow the best compatibility with clients.
+
+- Set `public.protocol` to the number matching that of your server version
+  (see [this](#list-of-versions) list)
+- Set `public.version` to any string you like. Shows up in read in clients that
+  have an incompatibel protocol version number
+
+These are used as hint. `lazymc` will automatically use the protocol version of
+your Minecraft server once it has started at least once.

res/lazymc.toml

@@ -8,7 +8,7 @@
 # You can probably leave the rest as-is.
 #
 # You may generate a new configuration with: lazymc config generate
-# Or find the latest at: https://is.gd/WWBIQu
+# Or find the latest at: https://git.io/J1Fvq
 
 [public]
 # Public address. IP and port users connect to.
@@ -17,7 +17,7 @@
 
 # Server version & protocol hint.
 # Sent to clients until actual server version is known.
-# See: https://is.gd/FTQKTP
+# See: https://git.io/J1Fvx
 #version = "1.17.1"
 #protocol = 756
 
@@ -30,7 +30,7 @@
 directory = "."
 
 # Command to start the server.
-# Warning: if using a bash script read: https://is.gd/k8SQYv
+# Warning: if using a bash script read: https://git.io/J1FvZ
 command = "java -Xmx1G -Xms1G -jar server.jar --nogui"
 
 # Immediately wake server when starting lazymc.