Add new images to manifest docs

1 files changed, 11 insertions, 2 deletions

diff --git a/builds.sr.ht/manifest.md b/builds.sr.ht/manifest.md
index a6f7972..688496c 100644
--- a/builds.sr.ht/manifest.md
+++ b/builds.sr.ht/manifest.md
@@ -40,8 +40,12 @@ Which OS image to build in. A list of available build images can be found
 
 *list* (of *string*)
 
-A list of package names to install on the image. The details of this process
-varies from image to image.
+A list of package names to install on the image.
+
+- **Alpine** installs these packages with `apk`
+- **Arch Linux** installs these packages with `yay`
+- **Debian** installs these packages with `apt-get install`
+- **FreeBSD** installs these packages with `pkg`
 
 ## repositories
 
@@ -50,6 +54,10 @@ varies from image to image.
 A list of extra repositories to enable with the image's package manager.
 The format is name: url, and the syntax of url varies between images.
 
+- **Alpine** uses `repo-url key-url key-name`, where `repo-url` is the URL of
+  the package repository and `key-url` is a URL from where the signing key may
+  be downloaded, and `key-name` is the name of the file written to
+  `/etc/apk/keys/`.
 - **Arch Linux** uses `url#key-id`, where `url` is the URL of the package
   repository and `key-id` is the ID of the published PGP key the packages are
   signed with.
@@ -57,6 +65,7 @@ The format is name: url, and the syntax of url varies between images.
   package repository, `distro` is e.g. `jessie` or `stretch`, `component` is
   e.g. `main` or `non-free`, and `key-id` is an optional PGP key ID to add to
   apt-key.
+- **FreeBSD** images do not support extra package repositories.
 
 ## sources