Add description to SET_PED_DENSITY_MULTIPLIER_THIS_FRAME

[Aloncheeto]

Add comments for better understanding.

[spacevx]

At this point, you can add examples from Lua, JS, or C#

-- 0.0 means no peds, while 1.0 indicates the regular density of peds.
local pedsDensityFactor = 0.0 

Citizen.CreateThread(function()
   while true do
       SetPedDensityMultiplierThisFrame(pedsDensityFactor)
       Citizen.Wait(0)    
   end
end)

JavaScript

// 0.0 means no peds, while 1.0 indicates the regular density of peds.
const pedsDensityFactor = 0.0;

setTick(() => {
    SetPedDensityMultiplierThisFrame(pedsDensityFactor);  
});

and for C# i'm not sure so i'm not going to write it

[4mmonium]

Approving this PR, thank you all for your contribution 🙂