update contributions and add tools readme

docs/CONTRIBUTING.md

@@ -110,14 +110,16 @@ To create your own feature or update, you should fork the repository and create
 a new branch based on the `latest` branch. Don't forget to update the ChangeLog
 with your changes, and when you're ready open a pull request against `latest`.
 
-It is unusual, but you may find that it is more appropriate to base your branch
-on the `release` branch instead of `latest`. Some examples of these types of
-changes are:
- * updates to project documentation that is relevant to the current version of
-   the project as well as the next
- * patches that need to be applied to the current version of the library in
-   order to fix broken functionality (note that this will require updating the
-   library to the next patch level, for example from 1.3.2 to 1.3.3)
+It is unusual, but you may find that it is best to base your work on the
+`release` branch instead of `latest`. This is a lot more work than using
+`latest` though, since the changes still need to be merged into `latest` which
+may have diverged enough to cause conflicts. It will also probably require
+cutting a new patch-level release with the changes. So don't do this unless
+it's truly necessary, as in these cases:
+ * patches need to be applied to the last release in order to fix broken
+   functionality
+ * critical updates to documentation that could cause serious misuse or breakage
+   if not corrected
 
 Be sure to check out the [dependencies](dependencies.md) list to make sure that
 your development environment has all of the necessary tools. More specifically,

tools/README.md

@@ -0,0 +1,37 @@
+# Development Tools
+Stumpless uses both custom and external tools to make development easier,
+implement features, and maintain the code base. This directory has files that
+are specific to these tools such as configuration files and scripts.
+
+
+## [`check_headers`](./check_headers)
+A custom tool written to make sure that appropriate headers are included in
+sources according to project conventions.
+
+
+## [`cmake`](./cmake)
+CMake scripts used in the configuration and build of Stumpless.
+
+
+## [`doxygen`](./doxygen)
+Configuration files for generating project documentation with Doxygen.
+
+
+## [`pkg-config`](./pkg-config)
+Configuration for `pkg-config` support.
+
+
+## [`portage`](./portage)
+Packaging files for Gentoo's Portage system.
+
+
+## [`sonar`](./sonar)
+Configuration for Sonarcloud code scanning and analysis.
+
+
+## [`valgrind`](./valgrind)
+Configuration files for valgrind, including false positive annotations.
+
+
+## [`wrapture`](./wrapture)
+Templates for generating C++ language bindings with Wrapture.