fix notes on updating submodules

.gitmodules

@@ -247,3 +247,6 @@
 [submodule "pkg/forklift-git"]
 	path = pkg/forklift-git
 	url = https://aur.archlinux.org/forklift-git.git
+[submodule "pkg/dotfiles"]
+	path = pkg/dotfiles
+	url = https://git.privacy1st.de/langfingaz/dotfiles.git

README.md

@@ -21,27 +21,11 @@ To initialize the submodules, run
 git submodule init
 ```
 
-To update all submodules and print a list of those who received an update, run
+To update all submodules and add those who received an update to
+[build-pkg/pkglist.tmp](build-pkg/pkglist.tmp), run
 
 ```shell
-if output="$(git submodule update --remote 2>&1)"; then
-  # We capture only the part after "pkg" until the next "'" using sed
-  # Source: https://unix.stackexchange.com/a/165590/315162 
-  sed 's|^Submodule path '\''pkg/\([^'\'']*\).*|\1|' <<< "$output"
-else
-  echo "$output"
-fi
-```
-
-It may happen that some submodules have a detached HEAD (due to local changes, etc.)
-and do not get updated with the above command. One can list those submodules as follows:
-
-```shell
-git submodule status | grep --invert-match '(heads/master)$'
-
-# One could then reset them to master with e.g.
-# git reset --hard
-# git checkout master
+git submodule foreach 'if git pull | grep '\''^Updating'\''; then printf " %s" "$(basename $sm_path)" >> $toplevel/build-pkg/pkglist.tmp; fi'
 ```