Add new images for Standard Base Documentation (#463)

* Add new images for Standard Base Documentation

Author: spier

assets/img/standard-base-documentation/CONTRIBUTING-for-contributors.png

@@ -0,0 +1,11 @@
+# Credits
+
+The current illustration is a digital remake of this [original visual](/patterns/2-structured/project-setup/assets/base_docs_drawing.png).
+If you want to edit this illustration, please request access to this [source document](https://docs.google.com/presentation/d/11JOByEO9QXlRLXX5BIv9rjUzPzCKErZzknD1OLcprQQ/edit?usp=sharing).
+
+The humans in the illustration are [bro](https://storyset.com/illustration/coding/bro) and [pana](https://storyset.com/illustration/high-five/pana) from Storyset.
+
+See:
+
+- [Web illustrations by Storyset](https://storyset.com/web)
+- [People illustrations by Storyset](https://storyset.com/people)

assets/img/standard-base-documentation/README-for-users.png

@@ -61,6 +61,8 @@ contain:
 * A "Who we are" section explaining who the [Trusted Committers](../trusted-committer.md) behind the project are - with an explanation that instead of contacting these people privately the public communication channels above should be used for communication.
 * An explanation of what the criteria are for the project to turn contributors into Trusted Committers - if that path exists.
 
+![README.md](../../../assets/img/standard-base-documentation/README-for-users.png)
+
 ### CONTRIBUTING.md
 
 If the explanation of the steps to make a contribution are too involved, create
@@ -77,7 +79,7 @@ topics:
 * How to submit your modifications back to the project.
 * Some information on which turnaround time to expect for modifications made.
 
-![Brief picture of README.md and CONTRIBUTING.md content](./assets/base_docs_drawing.png)
+![CONTRIBUTING.md](../../../assets/img/standard-base-documentation/CONTRIBUTING-for-contributors.png)
 
 There are many of good examples for how to write a `README.md` and what kind
 of information to include in a `CONTRIBUTING.md` file in various open source projects.
@@ -125,3 +127,7 @@ Provide standard base documentation through a README
 
 * [README-template.md](templates/README-template.md) and
 * [CONTRIBUTING-template.md](templates/CONTRIBUTING-template.md)
+
+## Credits
+
+[Web](https://storyset.com/web) and [People](https://storyset.com/people) illustrations by Storyset