[Docs] Add examples to set values in tasks via HTTP/MQTT

[TD-er]

For example:
How to set a value in a "Level" task, as asked on the forum

But there have been a few more plugins which support "config" like command syntax.
So maybe we should add some Example pages which can be included in several plugin pages to whom it applies.

[popaserge]

Example as requested to set values in tasks via HTTP/MQTT :

There is a general syntax for http commands that I tried to use : https://espeasy.readthedocs.io/en/latest/Reference/Command.html

For 3 years I use a Sonoff_4CH_Pro_R2 on which is installed ESP_Easy_mega_20210503_normal_ESP8285_1M.

Last summer I used the P001_Switch.ino plugin ( https://espeasy.readthedocs.io/en/latest/Plugin/P001.html) and 2 of the relays to manage 2 solenoid valves.

One of the solenoid valve is activated every evening at 21h to water my little vegetable garden during 10 mn.
This is made by following rules.

on System#Boot do
Let,4,600 // %v4% Temps de cycle arrosage 10 mn
endon
on Clock#Time=All,: do //will run every minute
if %syshour% = 21 and %sysmin% = 0
LongPulse,15,1,%v4% //Déclenchement relais 4 arrosage à 21h
endon

But this also works by http request on my smartphone to test it during 1 mn.
http//:192.168.xxx.yyy/control?cmd=Longpulse,15,1,60

The other valve is used to fill my swimming pool when necessary. This is done on my smartphone by an other http request:
http//:192.168.xxx.yyy/control?cmd=Longpulse,4,1,600

To send the http request I use the smartphone application Http Shortcuts (for Android)

I think that the same should be possible with the commands of the P021_Level.ino (https://espeasy.readthedocs.io/en/latest/Plugin/P021.html) or other similar plugins having specific commands to set a level or a value.