Fix typo in exec input readme (#7086)

plugins/outputs/exec/README.md

@@ -12,7 +12,7 @@ On non-zero exit stderr will be logged at error level.
 
 ```toml
 [[outputs.exec]]
-  ## Command to injest metrics via stdin.
+  ## Command to ingest metrics via stdin.
   command = ["tee", "-a", "/dev/null"]
 
   ## Timeout for command to complete.

plugins/outputs/exec/exec.go

@@ -26,7 +26,7 @@ type Exec struct {
 }
 
 var sampleConfig = `
-  ## Command to injest metrics via stdin.
+  ## Command to ingest metrics via stdin.
   command = ["tee", "-a", "/dev/null"]
 
   ## Timeout for command to complete.