website: docs: add oxford comma + simplify example (#6452)

* website: docs: add oxford comma

In this case, an oxford comma removes ambiguity.

Signed-off-by: Frank Villaro-Dixon <[email protected]>

* website: docs: tutorial: simplify example

The `RequeueAfter` example looks complicated (no mention of `nextRun`),
so add a simple `time.Minute` expression instead.

Signed-off-by: Frank Villaro-Dixon <[email protected]>

---------

Signed-off-by: Frank Villaro-Dixon <[email protected]>

Author: Frankkkkk

website/content/en/docs/best-practices/best-practices.md

@@ -11,7 +11,7 @@ Considerations for Operator developers:
 
 - An Operator should manage a single type of application, essentially following the UNIX principle: do one thing and do it well.
 
-- If an application consists of multiple tiers or components, multiple Operators should be written one for each of them. For example, if the application consists of Redis, AMQ and MySQL, there should be 3 Operators, not one.
+- If an application consists of multiple tiers or components, multiple Operators should be written one for each of them. For example, if the application consists of Redis, AMQ, and MySQL, there should be 3 Operators, not one.
 
 - If there is significant orchestration and sequencing involved, an Operator should be written that represents the entire stack, in turn delegating to other Operators for orchestrating their part of it.
 

website/content/en/docs/building-operators/golang/tutorial.md

@@ -293,7 +293,7 @@ The following are a few possible return options for a Reconciler:
   ```
 - Reconcile again after X time:
   ```go
-   return ctrl.Result{RequeueAfter: nextRun.Sub(r.Now())}, nil
+   return ctrl.Result{RequeueAfter: 5 * time.Minute}, nil
    ```
 
 For more details, check the Reconcile and its [Reconcile godoc][reconcile-godoc].