Update website and contributors guide.

Author: ztangent

CONTRIBUTING.md

@@ -34,7 +34,6 @@
 
 - In the introduction section(s), provide at least a few sentences of high-level description of the feature, to orient the user. Include external links and internal links. Then, include some short code snippets showing a minimal example of the feature being used. If relevant, include some simple Tex math.
 
-- Build the docs locally to test that it builds and looks right:
-```sh
-./docs/build_docs_locally.sh
-```
+- Build the docs locally to test that it builds and looks right.
+
+- Once you have a made a PR and are assigned a PR `NUMBER`, update your PR description with a link to the automatically generated documentation preview at https://www.gen.dev/docs/previews/PR{NUMBER}.

WEBSITE.md

@@ -1,21 +1,24 @@
-The Gen website is hosted on Github pages at https://probcomp.github.io/Gen/
+The Gen website is hosted at https://www.gen.dev/.
 
 The website is generated from the source files that are at the head commit of the `gh-pages` branch of the Gen repository.
 
 To edit the website, check out the `gh-pages` branch, and commit and push changes.
 
-Automatically-generated Gen documentation is pushed to the `gh-pages` branch whenever a commit is made to the `master` branch of the Gen repository using a combination of Github Actions and Documenter.jl, which are configured in the files `.github/workflows/Documentation.yml` and `docs/make.jl` in the `master` branch.
+Automatically-generated Gen documentation is pushed to the `docs` folder of the `gh-pages` branch whenever a commit is made to the `master` branch of the Gen repository using a combination of Github Actions and Documenter.jl, which are configured in the files `.github/workflows/Documentation.yml` and `docs/make.jl` in the `master` branch. When a pull request is merged into the `master` branch, the `gh-pages` branch is updated with the new documentation, and documentation previews will be cleaned up by the `.github/workflows/Documentation.yml` workflow.
+
 The automatically-managed files and directories are:
 
-- `dev/` (documentation for the version of Gen on the head of `master` branch)
+- `docs/dev/` (documentation for the version of Gen on the head of `master` branch)
+
+- `docs/v*.*.*/` (directories that contain documentation for each tagged release of Gen)
 
-- `v*.*.*/` (directories that contain documentation for each tagged release of Gen)
+- `docs/latest/` (a symbolic link to `dev/`)
 
-- `latest/` (a symbolic link to `dev/`)
+- `docs/stable/` (a symbolic link to the documentation directory of the latest tagged release Gen)
 
-- `stable/` (a symbolic link to the documentation directory of the latest tagged release Gen)
+- `docs/previews/` (documentation previews for unmerged pull requests)
 
-- `versions.js`
+- `docs/versions.js`
 
 *Do not make commits that modify the contents of these automatically managed files and directories.*