Include symbols in command pattern

This fixes some math commands which previously could not be invoked

Author: fwcd

Sources/D2Handlers/Message/Handler/CommandHandler.swift

@@ -38,7 +38,7 @@ private struct RunnablePipe: AsyncRunnable {
 // The first group matches the command name,
 // the second matches the iteration count and
 // the third the arguments (the rest of the message content)
-nonisolated(unsafe) private let commandPattern = #/(?<name>\w+)(?:\^(?<iterations>\d+))?(?:\s+(?<args>[\s\S]*))?/#
+nonisolated(unsafe) private let commandPattern = #/(?<name>[\w+\-*\/%]+)(?:\^(?<iterations>\d+))?(?:\s+(?<args>[\s\S]*))?/#
 
 /// Handles (possibly piped or chained) command invocations.
 public class CommandHandler: MessageHandler {