Merge pull request #49 from ErwannLesech/pretty-print2

doc<README>: add some important content in README

README.md

@@ -8,7 +8,9 @@
 
 - [Installation](#installation)
 - [Usage](#usage)
+- [Features](#features)
 - [Contributing](#contributing)
+- [Contious Integration](#continuous-integration)
 
 ## Installation
 
@@ -52,6 +54,42 @@ $ ./42sh --logger # Print some informations during process
 $ ./42sh --pretty-print # Print the parser AST
 ```
 
+In case of `pretty-print` option, a `.gv` file is generated. To convert it to a `.png` to visualise the ast, here is the line:
+
+```sh
+dot -Tpng pretty_print.gv -o ast.png
+display ast.png
+```
+
+## Features
+
+In the 42sh project, our primary objective was to implement a comprehensive set of POSIX features. 
+
+These features include, but are not limited to, what follows : 
+
+*Each step represents every week working on the project.*
+
+### Step 1
+
+- **Conditionnal operators** (if, elif, else, fi)
+- **Commands list** (echo ; ls)
+- **Single quote strings** (echo 'It is an \\'exemple\\'')
+- **Comments** (echo exem# it is a comment)
+- **Simple commands** (echo, ls, cat, tr, ...)
+- **Simple builtins** (true, false, echo -enE)
+
+### Step 2
+
+- **Redirections** (>, <, >>, >&, <&, >|, <>)
+- **Pipes** (echo dad | tr a e)
+- **Negation** (! true)
+- **Basic loops** (while, until)
+- **Operators** (&&, ||)
+- **Double quote strings** (echo "This variable $a is an amount in \$")
+- **Variables** (a=2, $a, $#, $*, $RANDOM, $UID, $IFS, ...)
+- **For loops**
+
+
 ## Contributing
 
 All contributions are done by doing a merge request when you are done working on your own branch
@@ -106,3 +144,19 @@ fix(http_parser): use the correct HTTP response code for wrong version
  
 Use the HTTP error 405 instead of 400 if the request contains an unsupported HTTP version.
 ```
+
+## Continuous Integration
+
+Powered by LESECH Erwann.
+
+At every `push/pull_request` to `master` and `dev`, the CI is executed to check some rules and deploy the result to gh-pages.
+
+Here are main rules to respect in order to check the CI program:
+
+- `configure.ac` and `Makefile.am` are used to compile and run the testsuite of 42Sh.
+
+- `.clang-format` is used to diff the whole project and check if it's clang-format compliant.
+
+- `github/workflows/clang_tidy.sh` is a shell script that verify if the 42Sh is clang-tidy compliant.
+
+- `Doxyfile` must be pushed to be used with `doxygen` in order to generate the documentation.