Create usermods folder (#389)

usermods/readme.md

@@ -0,0 +1,18 @@
+### Usermods
+
+This folder serves as a repository for usermods (custom `wled06_usermod.ino` files)!
+
+If you have created an usermod that you believe is useful (for example to support a particular sensor, display, feature...), feel free to contribute by opening a pull request!
+
+In order for other people to be able to have fun with your usermod, please keep these points in mind:
+
+- Create a folder in this folder with a descriptive name (for example `usermod_ds18b20_temp_sensor_mqtt`)  
+- Include your custom `wled06_usermod.ino` file
+- If your usermod requieres changes to other WLED files, please write a `readme.md` outlining the steps one has to take to use the usermod
+- Create a pull request!
+- If your feature is useful for the majority of WLED users, I will consider adding it to the base code!
+
+While I do my best to not break too much, keep in mind that as WLED is being updated, usermods might break.  
+I am not actively maintaining any usermod in this directory, that is your responsibility as the creator of the usermod.
+
+Thank you for your help :)

wled00/FX_fcn.cpp

@@ -69,7 +69,7 @@ void WS2812FX::service() {
         doShow = true;
         handle_palette();
         uint16_t delay = (this->*_mode[SEGMENT.mode])();
-        SEGENV.next_time = millis() + delay;
+        SEGENV.next_time = nowUp + delay;
         if (SEGMENT.mode != FX_MODE_HALLOWEEN_EYES) SEGENV.call++;
       }
     }