Add notes on updating Alpine/Conda packages

Closes #1863
Closes #1864

HOWTORELEASE.txt

@@ -143,3 +143,28 @@ Release Process
     ::
 
         http://upload.osgeo.org/cgi-bin/osgeo4w-promote.sh
+
+12) Update Alpine package
+
+  - The PDAL Alpine package lives at
+    https://github.com/alpinelinux/aports/blob/master/testing/pdal/APKBUILD.
+    Pull requests can be made against the alpinelinux/aports repository. If the
+    build configuration alone is changing, with no version increase, simply
+    increment the build number `pkgrel`. If the `pkgver` is changing, then
+    reset `pkgrel` to 0.
+  - Pull requests should have a commit message of the following form
+    `testing/pdal: <description>`.
+
+13) Update Conda package
+
+  - For PDAL releases that bump version number, but do not change dependencies
+    or build configurations, the `regro-cf-autotick-bot` should automatically
+    create a pull request at https://github.com/conda-forge/pdal-feedstock.
+    Once the builds succeed, the PR can be merged and the updated package will
+    soon be available in the `conda-forge` channel. If the PR does not build
+    successfully, updates to the PR can be pushed to the bot's branch. Version
+    bumps should reset the build number to zero.
+  - Updates that alter the build configuration but do not bump the version
+    number should be submitted as PRs from a fork of the
+    https://github.com/conda-forge/pdal-feedstock repository. In these cases,
+    the build number should be incremented.