Add pip / conda install instructions, and contribution guide

Contribution guide derived from:

https://github.com/rapidsai/pynvjitlink/blob/main/CONTRIBUTING.md

Author: gmarkall

CONTRIBUTING.md

@@ -0,0 +1,62 @@
+# Contributing to Numba-CUDA
+
+If you are interested in contributing to Numba-CUDA, your contributions will fall
+into three categories:
+1. You want to report a bug, feature request, or documentation issue
+    - File an [issue](https://github.com/NVIDIA/numba-cuda/issues/new/choose)
+    describing what you encountered or what you want to see changed.
+    - The Numba-CUDA team will evaluate the issues and triage them. If you
+      believe the issue needs priority attention comment on the issue to notify
+      the team.
+2. You want to propose a new Feature and implement it
+    - Post about your intended feature, and we shall discuss the design and
+    implementation.
+    - Once we agree that the plan looks good, go ahead and implement it, using
+    the [code contributions](#code-contributions) guide below.
+3. You want to implement a feature or bug-fix for an outstanding issue
+    - Follow the [code contributions](#code-contributions) guide below.
+    - If you need more context on a particular issue, please ask and we shall
+    provide.
+
+## Code contributions
+
+### Your first issue
+
+1. Read the project's [README.md](https://github.com/NVIDIA/numba-cuda/blob/main/README.md)
+    to learn how to setup the development environment
+2. Find an issue to work on.
+3. Comment on the issue saying you are going to work on it
+4. Code! Make sure to update unit tests!
+5. When done, [create your pull request](https://github.com/NVIDIA/numba-cuda/compare)
+6. Verify that CI passes all [status checks](https://help.github.com/articles/about-status-checks/). Fix if needed
+7. Wait for other developers to review your code and update code as needed
+8. Once reviewed and approved, a Numba-CUDA developer will merge your pull request
+
+Remember, if you are unsure about anything, don't hesitate to comment on issues
+and ask for clarifications!
+
+## Releases
+
+The release process for Numba-CUDA involves the following steps:
+
+- Open a PR to update `numba_cuda/VERSION` to the desired version.
+- Generate a short changelog with `git log v<PREVIOUS_VERSION>..HEAD --oneline --pretty=format:"- %s"`
+- Put the changelog in the version update PR description.
+- Once `main` is updated, tag the release:
+```
+git checkout main && git pull
+git tag -a v<VERSION>
+```
+- For the tag annotation, paste the same changelog as above, like this:
+```
+v<VERSION>
+
+- ... (bullet points on release items)
+```
+- Push the tag:
+```
+git push [email protected]:NVIDIA/numba-cuda.git v<VERSION>
+```
+
+## Attribution
+Portions adopted from https://github.com/pytorch/pytorch/blob/master/CONTRIBUTING.md

README.md

@@ -12,7 +12,19 @@ tracker](https://github.com/NVIDIA/numba-cuda/issues).
 To raise questions or initiate discussions, please use the [Numba Discourse
 forum](https://numba.discourse.group).
 
-## Building from source
+## Installation with pip
+
+```shell
+pip install numba-cuda
+```
+
+## Installation with Conda
+
+```shell
+conda install -c conda-forge numba-cuda
+```
+
+## Installation from source
 
 Install as an editable install:
 
@@ -38,3 +50,9 @@ which will show a path like:
 ```
 <path to numba-cuda repo>/numba_cuda/numba/cuda/__init__.py
 ```
+
+## Contributing Guide
+
+Review the
+[CONTRIBUTING.md](https://github.com/NVIDIA/numba-cuda/blob/main/CONTRIBUTING.md)
+file for information on how to contribute code and issues to the project.