[doc] minor updates

README.md

@@ -39,7 +39,7 @@ Documentation regarding the usage and installation is available at <https://hep-
 - Command-line scripts for common workflows (`colibri`, `evolve_fit`, etc.)
 - Integration with external PDF model repositories
 
-<img src="./colibri-diagram-hessian.png" alt="colibri diagram" width="90%">
+<img src="./colibri-diagram-blackjax.png" alt="colibri diagram" width="90%">
 
 ---
 

colibri/doc/README.md

@@ -1,3 +1,5 @@
 # Colibri code and standards documentation <a name="top"></a>
 
-Here we store the `documentation <https://hep-pbsp.github.io/colibri/index.html>`_. 
+Here we store Colibri's [documentation](https://hep-pbsp.github.io/colibri/index.html). 
+
+For instructions on how to contribute to the documentation see the [guidelines](https://hep-pbsp.github.io/colibri/get-started/document.html).

colibri/doc/sphinx/source/get-started/index.rst

@@ -16,3 +16,4 @@ If you use the public Colibri code, please cite all references listed in :ref:`c
   ./installation.rst
   ./first-fit.rst
   ./cite.rst
+  ./document.rst