docs: Add minimum versions to all the backend pages and some of the other pages

bin/backend-versions.sh

@@ -0,0 +1,17 @@
+#!/bin/bash
+# This adds the version each backend was released to its docs page
+set -e
+for backend in $( find backend -maxdepth 1 -type d ); do
+    backend=$(basename $backend)
+    if [[ "$backend" == "backend" || "$backend" == "vfs" || "$backend" == "all" || "$backend" == "azurefile" ]]; then
+        continue
+    fi
+    
+    commit=$(git log --oneline -- $backend | tail -1 | cut -d' ' -f1)
+    if [ "$commit" == "" ]; then
+        commit=$(git log --oneline -- backend/$backend | tail -1 | cut -d' ' -f1)
+    fi
+    version=$(git tag --contains $commit | grep ^v | sort -n | head -1)
+    echo $backend $version
+    sed -i~ "4i versionIntroduced: \"$version\"" docs/content/${backend}.md
+done