docs: remove link to no-longer-used stability level (#63)

In practice, stability levels do not provide additional meaning beyond
what is already in the license file. We are removing references to these
stability levels to avoid setting unintended expectations for differing
levels of maintenance.

README.md

@@ -1,6 +1,5 @@
 # Equinix Go SDK
 
-[![Maintained](https://img.shields.io/badge/stability-maintained-green.svg)](https://github.com/equinix-labs/equinix-labs/blob/main/maintained-statement.md)
 [![Release](https://img.shields.io/github/v/release/equinix/equinix-sdk-go)](https://github.com/equinix/equinix-sdk-go/releases/latest)
 [![GoDoc](https://godoc.org/github.com/equinix/equinix-sdk-go?status.svg)](https://godoc.org/github.com/equinix/equinix-sdk-go)