Removing old version notice

pkg/yqlib/doc/operators/add.md

@@ -9,12 +9,6 @@ Add behaves differently according to the type of the LHS:
 Use `+=` as a relative append assign for things like increment. Note that `.a += .x` is equivalent to running `.a = .a + .x`.
 
 
-{% hint style="warning" %}
-Note that versions prior to 4.18 require the 'eval/e' command to be specified. 
-
-`yq e <exp> <file>`
-{% endhint %}
-
 ## Concatenate arrays
 Given a sample.yml file of:
 ```yaml