Update Git basics and how I work with Git (#186)

* Update Git basics and how I work with Git

* Add link to bash PS1 trick

* Fix linting

01_version_control/git_basics_demo.md

@@ -37,31 +37,31 @@ Starting remarks:
     - fork -> my fork
 
 - (2) Working directory:
-    - ZSH shell shows git branches
+    - ZSH shell shows git branches. There are [similar solutions for Bash](https://coderwall.com/p/fasnya/add-git-branch-name-to-bash-prompt) as well.
     - `git remote -v` (I have upstream, myfork, ...)
     - mention difference between ssh and https (also see GitHub)
     - get newest changes `git pull upstream develop`
+    - or simply `git pull` (`git branch -vv` to see upstream tracking)
     - `git log` -> I use special format, see `~/.gitconfig`,
-    - check log on GitHub; explain short hash
-    - `git branch`
-    - `git branch add-demo-feature`
-    - `git checkout add-demo-feature`
+    - check log on GitHub
+    - explain how hash is computed (complete state + pointer to parent)
+    - explain short hash
+    - `git checkout -b add-demo-feature`
 
 - (3) First commit
     - `git status` -> always tells you what you can do
     - `vi src/action/Action.hpp` -> add `#include "MagicHeader.hpp"`
     - `git diff`, `git diff src/com/Action.hpp`, `git diff --color-words`
     - `git status`, `git add`, `git status`
     - `git commit` -> "Include MagicHeader in Action.hpp"
-    - `git status`, `git log`, `git log -p`, `git show`
+    - `git status`, `git log`, `git show`
 
-- (4) Change or revert things
+- (4) Change or reset things
     - I forgot to add sth: `git reset --soft HEAD~1`, `git status`
     - `git diff`, `git diff HEAD` because already staged
     - `git log`
     - `git commit`
     - actually all that is nonsense: `git reset --hard HEAD~1`
-    - modify again, all nonsense before committing: `git checkout src/action/Action.hpp`
 
 - (5) Stash
     - while working on unfinished feature, I need to change / test this other thing quickly, too lazy for commits / branches
@@ -70,7 +70,6 @@ Starting remarks:
 
 - (6) Create PR
     - create commit again
-    - preview what will be in PR: `git diff develop..add-demo-feature`
     - `git push -u myfork add-demo-feature` -> copy link
     - explain PR template
     - explain target branch
@@ -87,13 +86,17 @@ Starting remarks:
     - `git checkout -t alex/[branch-name]`
     - I could now also push to `ajaust`'s remote
 
+- (8) GitHub CLI
+    - `git push -u ...` and `git pull -t ...` maybe hard to remember at first.
+    - Things get easier with the [GitHub CLI](https://cli.github.com/), but bound to GitHub, obviously.
+
 ## Further reading
 
 ### Quick things
 
 - [Video: Git in 15 minutes: basics, branching, no remote](https://www.youtube.com/watch?v=USjZcfj8yxE)
 - [The GitHub Blog: Commits are snapshots, not diffs](https://github.blog/2020-12-17-commits-are-snapshots-not-diffs/)
-- Chapters [6](https://merely-useful.tech/py-rse/git-cmdline.html) and [7](https://merely-useful.tech/py-rse/git-advanced.html) of Research Software Engineering with Python
+- Chapters [6](https://third-bit.com/py-rse/git-cmdline.html) and [7](https://third-bit.com/py-rse/git-advanced.html) of Research Software Engineering with Python
 - [Podcast All Things Git: History of VC](https://www.allthingsgit.com/episodes/the_history_of_vc_with_eric_sink.html)
 - [git purr](https://girliemac.com/blog/2017/12/26/git-purr/)