Update README.md

Add CoAP & cellular networks (#4)
Add Secure Boot and OTA (#3)
Add Functional Safety
Add MATLAB / Simulink

README.md

@@ -2,15 +2,18 @@
 
 This is a roadmap for those who want to build a career as an Embedded Developer or Embedded Engineer.
 In order to assist beginners, steps have been taken to create a roadmap that is straightforward and easy to understand.
+Topics in the roadmap are primarily selected based on open job requirements and organized according to my own experience.
 
-If you think that this map can be improved in anyway, please start an issue or pull request. I’ll be maintaining and updating this repository frequently. The source file is created using [Microsoft Visio](https://office.com/visio).
+If you think that this map can be improved in anyway, please start an issue or pull request. I’ll be maintaining and updating this repository frequently.
 
-![Embedded Systems Engineering Roadmap](https://github.com/m3y54m/Embedded-Engineering-Roadmap/releases/download/Rev.E-2023-07-27/Embedded-Engineering-Roadmap.png)
+The source file is created using [Microsoft Visio](https://office.com/visio) in `.vsdx` format and included in this repository for your contributions. If you do not have Microsoft Visio or you want to use free software, you can use [draw.io](https://draw.io) which can import and export `.vsdx` files.
+
+![Embedded Systems Engineering Roadmap](https://github.com/m3y54m/Embedded-Engineering-Roadmap/releases/download/Rev.J-2023-07-29/Embedded-Engineering-Roadmap.png)
 
 ## History
 
-The idea of creating this roadmap came from a [roadmap](https://github.com/vazeri/Embedded-Engineering-RoadMap-2018) designed by [vazeri](https://github.com/vazeri) which was well designed but not updated for years.
-I took that idea and changed the structure of the roadmap and tried to improve it. The initial results can be accessed in [m3y54m / Embedded-Engineering-Roadmap-Archived](https://github.com/m3y54m/Embedded-Engineering-Roadmap-Archived) which is now archived. Early versions of the roadmap were created using [Balsamiq Wireframes](https://balsamiq.com) which were not suitable for these types of diagrams. So I decided to use Microsoft Visio and redrew the whole diagram with it.
+The idea of creating this roadmap came from [vazeri / Embedded-Engineering-RoadMap-2018](https://github.com/vazeri/Embedded-Engineering-RoadMap-2018) which was well designed but had some flaws and not updated for years.
+I took that idea, changed the structure of the roadmap and tried to improve it. The initial results can be accessed in [m3y54m / Embedded-Engineering-Roadmap-Archived](https://github.com/m3y54m/Embedded-Engineering-Roadmap-Archived) which is now archived. Early versions of the roadmap were created using [Balsamiq Wireframes](https://balsamiq.com) which is not suitable for these types of diagrams. So I decided to use Microsoft Visio instead and redrew the whole diagram.
 
 ## Copyright