Fix: Broken link to r2d2 docs
I'm assuming the intention is to link to the current r2d2 crate docs from the ConnectionManager struct. Changed it to refer to
@@ -115,9 +115,7 @@ use crate::query_builder::{Query, QueryFragment, QueryId};
/// An r2d2 connection manager for use with Diesel.
///
-/// See the [r2d2 documentation] for usage examples.
-///
-/// [r2d2 documentation]: r2d2
+/// See the [r2d2 documentation](https://docs.rs/r2d2/latest/r2d2/) for usage examples.
#[derive(Clone)]
pub struct ConnectionManager<T> {
database_url: String,
