Adding in deleted scarf pixel for analytics tracking on lua filter docs.

Signed-off-by: Eric D. Schabell <[email protected]>

Author: eschabell

pipeline/filters/lua.md

@@ -1,5 +1,7 @@
 # Lua
 
+<img referrerpolicy="no-referrer-when-downgrade" src="https://static.scarf.sh/a.png?x-pxid=f519378e-536c-4b25-8949-ee6ed8d8d6c1" />
+
 The _Lua_ filter lets you modify incoming records (or split one record into multiple records) using custom [Lua](https://www.lua.org/) scripts.
 
 A Lua-based filter requires two steps:
@@ -804,4 +806,4 @@ pipeline:
 
 ```text
 test: [[1731990257.781970977, {}], {"my_env"=>{"A"=>"aaa", "C"=>"ccc", "HOSTNAME"=>"monox-2.lan", "B"=>"bbb"}, "rand_value"=>4805047635809401856}]
-```
+```