diff --git a/diagram.svg b/diagram.svg
index c8cedf3..d95bdc1 100644
--- a/diagram.svg
+++ b/diagram.svg
@@ -1 +1 @@
-
\ No newline at end of file
+
\ No newline at end of file
diff --git a/git/README.md b/git/README.md
index ddec039..b78d239 100644
--- a/git/README.md
+++ b/git/README.md
@@ -1,4 +1,6 @@
-# get help
+# Git
+
+## get help
```
git help # in general
git help tutorial # the very basics
@@ -8,11 +10,12 @@ git help blame
man git-blame
```
-# get a file from history to another location
- git show commit:filepath > location
+## best practice
+ git show commit:filepath > location # get a file from history to another location
+ git for-each-ref --format "%(authorname)" | sort -u # get all authors
-# todo
+## todo
* https://www.freecodecamp.org/news/git-under-the-hood/
* https://www.freecodecamp.org/news/how-to-write-better-git-commit-messages/
diff --git a/git/gitignore.md b/git/gitignore.md
new file mode 100644
index 0000000..995c011
--- /dev/null
+++ b/git/gitignore.md
@@ -0,0 +1,93 @@
+# Gitignore
+https://git-scm.com/docs/gitignore
+https://help.github.com/en/github/using-git/ignoring-files
+https://github.com/github/gitignore
+
+```
+file_pattern_to_exclude >> .gitignore
+nano .gitignore
+nano .git/info/exclude
+
+git rm –cached # stop tracking the file
+git rm -r --cached .
+git ls-files --ignored --exclude-standard
+git ls-files --ignored --exclude-standard | sed 's/.*/"&"/' | xargs git rm -r --cached
+
+git add .
+git commit -m ".gitignore: added …, removed …, changed …"
+git ls-files --other --directory #list of ignored files
+git push
+```
+
+## Whitelisting
+https://jasonstitt.com/gitignore-whitelisting-patterns
+```
+# typical
+*
+!*/
+*/some/dir3/**
+!.gitignore
+
+# for all dir content
+/*
+!/whitelisteddir1
+!/whitelisteddir2
+!.gitignore
+
+# to track only the dir but not the files in it
+*
+!.gitignore
+```
+
+
+## Windows user profile
+```
+.bash_history
+ntuser*
+
+Application Data/
+Anwendungsdaten/
+
+Cookies/
+Documents/My Music/
+Documents/My Pictures/
+Documents/My Videos/
+
+Local Settings/
+Lokale Einstellungen/
+
+My Documents/
+
+NetHood/
+Netzwerkumgebung/
+
+PrintHood/
+Druckumgebung/
+
+Recent/
+SendTo/
+
+Start Menu/
+Startmenü/
+
+Templates/
+Vorlagen/
+
+Appdata/
+Eigene Dateien/
+
+Downloads/
+Favorites/
+Links/
+Searches/
+
+*.log
+desktop.ini
+
+.ssh/id_rsa*
+.ssh/known_hosts
+```
+
+
+
+
diff --git a/github/README.md b/github/README.md
new file mode 100644
index 0000000..c1d19a9
--- /dev/null
+++ b/github/README.md
@@ -0,0 +1,16 @@
+# Github
+
+## Markup
+https://github.com/github/markup
+https://docs.github.com/en/get-started/writing-on-github/getting-started-with-writing-and-formatting-on-github/basic-writing-and-formatting-syntax
+
+Tables https://docs.github.com/en/get-started/writing-on-github/working-with-advanced-formatting/organizing-information-with-tables
+Diagrams https://docs.github.com/en/get-started/writing-on-github/working-with-advanced-formatting/creating-diagrams
+
+
+## Actions
+https://docs.github.com/en/actions/learn-github-actions/understanding-github-actions
+
+
+## Edu
+https://skills.github.com/
diff --git a/kubernetes/README.md b/kubernetes/README.md
new file mode 100644
index 0000000..60fff10
--- /dev/null
+++ b/kubernetes/README.md
@@ -0,0 +1,3 @@
+# Kubernetes
+https://www.edx.org/learn/kubernetes/the-linux-foundation-introduction-to-kubernetes
+https://kubernetes.io/training/#get-certified