feat(terra/autoupdate): weekly packages real

Author: madonuko

pages/terra/autoupdate.mdx

@@ -81,6 +81,26 @@ You can obtain the branch name during runtime in Rhai using `labels.branch` (str
   Consequently, under normal circumstances and without approval, you are NOT allowed to use GitHub/GitLab related functions.
 </Callout>
 
+#### Weekly packages
+
+Weekly packages are updated every 7 days using
+`anda update -vv --filters weekly=$(date "+%w"){:ansi}`.
+Their `anda.hcl` files should look something like this:
+
+```hcl
+project pkg {
+	rpm {
+		spec = "pkg.spec"
+	}
+	labels {
+		weekly = 0 # a random number between 0~6 inclusive
+	}
+}
+```
+
+To decide the random number, just search for "_random number between 0 and 6_" with your favourite search engine.
+The random number decides which day in the week will the auto-update script run.
+
 #### Functions and Modules
 
 In most cases, `rpm.version(gh("..."));{:ts}` as a one-liner is enough to make it work™.