Created PKI Best Practices in markdown (#48)

* - Updated version to 8.6.3
- Create Encryption document in Markdown format
- Added new Encryption document to SUMMARY.md for publishing.

* - Included package-lock.json

* Corrected reference in Encryption.md
Created PKI Best Practices in markdown
Recreated figure1-platforms-layout in drawio
Updated summary file for gitbooks
Updated version to 9.0.0

* Version update to 9.1.0

Co-authored-by: Sam <[email protected]>

Author: HenkKodde

SUMMARY.md

@@ -7,6 +7,7 @@
   * [API Definition v1.0](documents/API Definition v1.0.md)
   * [JSON Binding Rules](documents/JSON Binding Rules.md)
   * [Encryption](documents/Encryption.md)
+  * [PKI Best Practices](documents/PKI Best Practices.md)
 ### Change Control Board
 * [Change Control Board Overview](ccb-meetings/README.md)
   * [Issue-and-Decision-Log](ccb-meetings/Issue-and-Decision-Log.md)

assets/diagrams/images/figure1-platforms-layout.svg

@@ -49,7 +49,7 @@ The following conventions are used in this document to identify the specified ty
 | **Glossary terms** | Italics on first occurrence; defined in _Glossary_ | The purpose of the API is to enable interoperable financial transactions between a _Payer_ (a payer of electronic funds in a payment transaction) located in one _FSP_ (an entity that provides a digital financial service to an end user) and a _Payee_ (a recipient of electronic funds in a payment transaction) located in another FSP. |
 | **Library documents** | Italics | User information should, in general, not be used by API deployments; the security measures detailed in _API Signature_ and _API Encryption_ should be used instead. |
 
-## 2.1 Document Version Information
+## 1.2 Document Version Information
 
 | **Version** | **Date** | **Change Description** |
 | :--- | :--- | :--- |