Update comments in MinecraftCompressEncoder to be more accurate.

proxy/src/main/java/com/velocitypowered/proxy/protocol/netty/MinecraftCompressEncoder.java

@@ -38,9 +38,14 @@ public class MinecraftCompressEncoder extends MessageToByteEncoder<ByteBuf> {
   @Override
   protected ByteBuf allocateBuffer(ChannelHandlerContext ctx, ByteBuf msg, boolean preferDirect)
       throws Exception {
-    // Follow the advice of https://github.com/ebiggers/libdeflate/blob/master/libdeflate.h#L103
-    // here for compression. The maximum buffer size if the data compresses well (which is almost
-    // always the case) is one less the input buffer.
+    // We allocate bytes to be compressed plus 1 byte. This covers two cases:
+    //
+    // - Compression
+    //    According to https://github.com/ebiggers/libdeflate/blob/master/libdeflate.h#L103,
+    //    if the data compresses well (and we do not have some pathological case) then the maximum
+    //    size the compressed size will ever be is the input size minus one.
+    // - Uncompressed
+    //    This is fairly obvious - we will then have one more than the uncompressed size.
     int initialBufferSize = msg.readableBytes() + 1;
     return MoreByteBufUtils.preferredBuffer(ctx.alloc(), compressor, initialBufferSize);
   }