feat: Add a config option to change the max TL size for legacy sync

conduwuit-example.toml

@@ -1196,6 +1196,13 @@
 #
 #typing_client_timeout_max_s = 45
 
+# The maximum number of events to send at once for non-limited legacy syncs.
+# Has no effect on sliding sync. This parameter also affects how many messages from each room
+# are sent to the client on initial syncs, and larger values will make initial syncs slower.
+# The default of 10 is reasonable for most use cases.
+#
+#incremental_sync_max_timeline_size = 10
+
 # Set this to true for continuwuity to compress HTTP response bodies using
 # zstd. This option does nothing if continuwuity was not built with
 # `zstd_compression` feature. Please be aware that enabling HTTP