fix(mayastor): move mayastor content to gitbook

docs/architecture.md

@@ -167,7 +167,7 @@ In addition, OpenEBS also has released as alpha version `kubectl plugin` to help
 ## See Also:
 
 ### [Understanding Data Engines](/docs/next/casengines.html)
-### [Understanding Mayastor](/docs/next/mayastor.html)
+### [Understanding Mayastor](https://mayastor.gitbook.io/introduction/)
 ### [Understanding Local PV](/docs/next/localpv.html)
 ### [Understanding cStor](/docs/next/cstor.html)
 ### [Understanding Jiva](/docs/next/jiva.html)

docs/casengines.md

@@ -132,7 +132,7 @@ Replicated Volumes as the name suggests, are those that can synchronously replic
 
 Depending on the type of storage attached to your Kubernetes worker nodes and application performance requirements, you can select from [Jiva](/docs/next/jiva.html), [cStor](/docs/next/cstor.html) or [Mayastor](/docs/next/mayastor.html). 
 
-- [Mayastor](/docs/next/ugmayastor.html)
+- [Mayastor](https://mayastor.gitbook.io/introduction/)
 - [cStor](https://github.com/openebs/cstor-operators/blob/master/docs/quick.md)
 - [Jiva](https://github.com/openebs/jiva-operator)
 
@@ -230,7 +230,7 @@ A short summary is provided below.
 
 ## See Also:
 
-### [Mayastor User Guide](/docs/next/ugmayastor.html)
+### [Mayastor User Guide](https://mayastor.gitbook.io/introduction/)
 
 ### [cStor User Guide](/docs/next/ugcstor-csi.html)