R dependency is >=4.1.0

[Michael Chirico]

Hi, the examples for corrRect() induce a dependency on R >= 4.1.0.

Unfortunately, it's impossible to branch away usage of |> depending on the R version, because |> is not actually a function, but is interpreted by the parser. So the parser itself needs to know of |> in order for the example to parse, otherwise we get:

> if(getRversion() >= '4.1.0') {
+   corrplot(M, order = 'AOE') |> corrRect(namesMat = r)
Error: unexpected '>' in:

Please either add an explicit R version dependency or remove the examples (or put them in comments)

[Taiyun]

I will put them in comments.