updated README.md

Author: mohamed-barakat

README.md

@@ -17,14 +17,13 @@ The core part of the project is the [homalg package](https://homalg-project.gith
 
 The [other packages](https://homalg-project.github.io/homalg_project/) of the homalg project implement data structures and algorithms for several mathematical objects, like modules over graded rings or toric varieties.
 
-[docs-stable-img]: https://img.shields.io/badge/docs-stable-blue.svg
-[docs-stable-url]: https://homalg-project.github.io/homalg_project/
+This [slideshow](images/homalg-project.pdf) visualizes the interdependency of most of the packages in this repository:
 
-[tests-img]: https://github.com/homalg-project/homalg_project/workflows/Tests/badge.svg
-[tests-url]: https://github.com/homalg-project/homalg_project/actions?query=workflow%3ATests
+<center>
+<a href="https://docs.google.com/viewer?url=https%3A%2F%2Fhomalg-project.github.io%2Fhomalg_project%2Fimages%2Fhomalg-project.pdf" target="_blank"><img src="images/thumb.png" border="0" alt="the
+ homalg slideshow" title="the homalg slideshow" /></a>
+</center>
 
-[codecov-img]: https://codecov.io/gh/homalg-project/homalg_project/branch/master/graph/badge.svg
-[codecov-url]: https://codecov.io/gh/homalg-project/homalg_project
 <!-- BEGIN FOOTER -->
 [docs-homalg-img]: https://img.shields.io/badge/homalg-HTML-blue.svg
 [docs-homalg-url]: https://homalg-project.github.io/homalg_project/homalg/doc/chap0_mj.html