add docs for AWS CodeArtifact (#6816)

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## Summary

This adds explicit information about using `uv` with AWS CodeArtifact
(both as an extra index to fetch private packages and also to publish
packages using `twine`).

## Test Plan

I'm currently using this setup with several private projects that use
CodeArtifact.

---------

Co-authored-by: Zanie Blue <contact@zanie.dev>

docs/guides/integration/alternative-indexes.md

@@ -56,7 +56,60 @@ $ # Configure the index URL with the username
 $ export UV_EXTRA_INDEX_URL=https://VssSessionToken@pkgs.dev.azure.com/{organisation}/{project}/_packaging/{feedName}/pypi/simple/
 ```
 
+## AWS CodeArtifact
+
+uv can install packages from
+[AWS CodeArtifact](https://docs.aws.amazon.com/codeartifact/latest/ug/using-python.html).
+
+The authorization token can be retrieved using the `awscli` tool.
+
+!!! note
+
+    This guide assumes the AWS CLI has previously been authenticated.
+
+First, declare some constants for your CodeArtifact repository:
+
+```bash
+export AWS_DOMAIN="<your-domain>"
+export AWS_ACCOUNT_ID="<your-account-id>"
+export AWS_REGION="<your-region>"
+export AWS_CODEARTIFACT_REPOSITORY="<your-repository>"
+```
+
+Then, retrieve a token from the `awscli`:
+
+```bash
+export AWS_CODEARTIFACT_TOKEN="$(
+    aws codeartifact get-authorization-token \
+    --domain $AWS_DOMAIN \
+    --domain-owner $AWS_ACCOUNT_ID \
+    --query authorizationToken \
+    --output text
+)"
+```
+
+And configure the index URL:
+
+```bash
+export UV_EXTRA_INDEX_URL="https://aws:${AWS_CODEARTIFACT_TOKEN}@${AWS_DOMAIN}-${AWS_ACCOUNT_ID}.d.codeartifact.${AWS_REGION}.amazonaws.com/pypi/${AWS_CODEARTIFACT_REPOSITORY}/simple/"
+```
+
+### Publishing packages
+
+If you also want to publish your own packages to AWS CodeArtifact, you can use `twine` as described
+in the [publishing guide](../publish.md). You will need to set `TWINE_REPOSITORY_URL` separately
+from the credentials:
+
+```bash
+# Configure twine to use AWS CodeArtifact
+export TWINE_REPOSITORY_URL="https://${AWS_CODEARTIFACT_TOKEN}@${AWS_DOMAIN}-${AWS_ACCOUNT_ID}.d.codeartifact.${AWS_REGION}.amazonaws.com/pypi/${AWS_CODEARTIFACT_REPOSITORY}/"
+export TWINE_USERNAME=aws
+export TWINE_PASSWORD="$AWS_CODEARTIFACT_TOKEN"
+
+# Publish the package
+uv run twine upload dist/*
+```
+
 ## Other indexes
 
-uv is also known to work with JFrog's Artifactory, the Google Cloud Artifact Registry, and AWS Code
-Artifact.
+uv is also known to work with JFrog's Artifactory and the Google Cloud Artifact Registry.