Revise CONTRIBUTING.md

- Replace directory links with directory map
- Remove references to underway conversion, as that's about wrapped up
- Remove now-unused links
- Minor text updates

Author: Steve Hollasch

CONTRIBUTING.md

@@ -5,35 +5,36 @@ The _Ray Tracing in One Weekend_ series is intended to be lightweight and access
 want to learn about ray tracing and related graphics topics. To that end, we welcome feedback,
 proposals, and improvements.
 
-In particular, we have recently moved to a dedicated GitHub organization, and are working hard to
-get set up in the new location. On top of this, we're converting the books (already freely available
-to the public) to HTML, so that we can keep the content up-to-date with the latest corrections and
+In particular, we are now a dedicated GitHub organization. The books are now available in HTML from
+https://raytracing.github.io/, so we can keep the content up-to-date with the latest corrections and
 improvements.
 
-If you're interested in helping out, there are a number of ways you could help us. The most pressing
-right now is converting the books to [Markdeep][], a great Markdown-like format with lots of extra
-goodies (like mathematical equations and diagrams).
 
-Here are other ways you can help improve these books.
+Repository Organization
+------------------------
+This repository has the following organization
 
-
-Project Homes
---------------
-All books reside in their own directory in the `raytracing.github.io` repository.
-
-  - [_Ray Tracing in One Weekend_][]
-  - [_Ray Tracing: The Next Week_][]
-  - [_Ray Tracing: The Rest of Your Life_][]
+```bash
+raytracing.github.io/      # Repository root
+    books/                 # Book content
+    images/                # All figures, renderings and other images used throughout the project
+    src/                   # Source code
+        common/            # Source code that is common to two or more books
+        InOneWeekend/      # The final form of source code for Ray Tracing In One Weekend
+        TheNextWeek/       # The final form of source code for Ray Tracing: The Next Week
+        TheRestOfYourLife/ # The final form of source code for Ray Tracing: The Rest Of Your Life
+    style/                 # CSS for books and web site
+```
 
 
 Issues
 -------
 The easiest way to help out is to log any issues you find in the books. Unclear passages, errors of
 all kinds, even better ways to present something -- just go to the [issues page][].
 
-_Before creating a new issue_, please review existing issues to see if someone has already submitted
-the same one. Odds are you're not the first to encounter something, so a little quick research can
-save everyone some hassle.
+**Before creating a new issue**, please review existing issues to see if someone has already
+submitted the same one. Odds are you're not the first to encounter something, so a little quick
+research can save everyone some hassle.
 
 When entering a new issue, please include all relevant information. For content issues, include the
 book or books this applies to, and specific locations that should be reviewed. Similarly for code:
@@ -44,8 +45,9 @@ Pull Requests
 --------------
 If you have a change that you think would be worthwhile, start with creating an issue, and indicate
 whether you're willing to submit the change yourself. We'll let you know if it sounds like a good
-idea. If so, create your own fork of the project, make the changes, and then create a standard
-GitHub pull request for us to review.
+idea, whether it duplicates another issue or work already planned. If you get the green light,
+create your own fork of the project, make the changes, and then create a standard GitHub pull
+request for us to review.
 
 New to GitHub? We'll walk you through the process above. Just mention that you'd like a little
 guidance in the proposal issue.
@@ -57,8 +59,4 @@ If you have any questions, feel free to ping me at [email protected].
 
 
 
-[issues page]:                          https://github.com/RayTracing/raytracing.github.io/issues/
-[Markdeep]:                             https://casual-effects.com/markdeep
-[_Ray Tracing in One Weekend_]:         https://github.com/RayTracing/raytracing.github.io/tree/master/InOneWeekend
-[_Ray Tracing: The Next Week_]:         https://github.com/RayTracing/raytracing.github.io/tree/master/TheNextWeek
-[_Ray Tracing: The Rest of Your Life_]: https://github.com/RayTracing/raytracing.github.io/tree/master/TheRestOfYourLife
+[issues page]: https://github.com/RayTracing/raytracing.github.io/issues/