Add script to trim the repository

Reviewed-by: Aleix Boné <abonerib@bsc.es>

doc/trim.sh

@@ -0,0 +1,46 @@
+#!/bin/sh
+
+# Trims the jungle repository by moving the website to its own repository and
+# removing it from jungle. It also removes big pdf files and kernel
+# configurations so the jungle repository is small.
+
+set -e
+
+if [ -e oldjungle -o -e newjungle -o -e website ]; then
+  echo "remove oldjungle/, newjungle/ and website/ first"
+  exit 1
+fi
+
+# Clone the old jungle repo
+git clone gitea@tent:rarias/jungle.git oldjungle
+
+# First split the website into a new repository
+mkdir website && git -C website init -b master
+git-filter-repo \
+  --path web \
+  --subdirectory-filter web \
+  --source oldjungle \
+  --target website
+
+# Then remove the website, pdf files and big kernel configs
+mkdir newjungle && git -C newjungle init -b master
+git-filter-repo \
+  --invert-paths \
+  --path web \
+  --path-glob 'doc*.pdf' \
+  --path-glob '**/kernel/configs/lockdep' \
+  --path-glob '**/kernel/configs/defconfig' \
+  --source oldjungle \
+  --target newjungle
+
+set -x
+
+du -sh oldjungle newjungle website
+#  57M  oldjungle
+# 2,3M  newjungle
+# 6,4M  website
+
+du -sh --exclude=.git oldjungle newjungle website
+#  30M  oldjungle
+# 700K  newjungle
+# 3,5M  website