Update README and documentation.

README.md

@@ -7,6 +7,7 @@
  [![Code Coverage](https://img.shields.io/scrutinizer/coverage/g/loophp/collection/master.svg?style=flat-square)](https://scrutinizer-ci.com/g/loophp/collection/?branch=master)
  [![License](https://img.shields.io/packagist/l/loophp/collection.svg?style=flat-square)](https://packagist.org/packages/loophp/collection)
  [![Donate!](https://img.shields.io/badge/Sponsor-Github-brightgreen.svg?style=flat-square)](https://github.com/sponsors/drupol)
+ [![Donate!](https://img.shields.io/badge/Sponsor-Paypal-brightgreen.svg?style=flat-square)](https://www.paypal.me/drupol)
 
 # PHP Collection
 
@@ -57,7 +58,14 @@ Similar libraries:
 On top of a complete documented code, the package include a full documentation that gets automatically compiled
 and published upon each commit at [https://loophp-collection.rtfd.io](https://loophp-collection.rtfd.io).
 
-The documentation is missing some parts, it's being continuously improved with time.
+[The API](https://loophp-collection.readthedocs.io/en/latest/pages/api.html) will give you a pretty good idea of the
+existing methods and what you can do with it.
+
+Do not forget to check out the [usage](https://loophp-collection.readthedocs.io/en/latest/pages/usage.html) and
+[examples](https://loophp-collection.readthedocs.io/en/latest/pages/examples.html) pages. 
+
+I'm doing my best to keep the documentation up to date, if you found something odd, please let me know in the [issue
+queue](https://github.com/loophp/collection/issues).
 
 ## Code quality, tests and benchmarks
 
@@ -67,14 +75,23 @@ tests.
 The library has tests written with [PHPSpec](http://www.phpspec.net/).
 Feel free to check them out in the `spec` directory. Run `composer phpspec` to trigger the tests.
 
-Before each commit some inspections are executed with [GrumPHP](https://github.com/phpro/grumphp), 
+Before each commit some inspections (_currently 14_) are executed with [GrumPHP](https://github.com/phpro/grumphp), 
 run `./vendor/bin/grumphp run` to check manually.
 
-[PHPInfection](https://github.com/infection/infection) is used to ensure that your code is properly tested, run `composer infection` to test your code.
+The quality of the tests is tested with a PHP Mutation testing framework,  run `composer infection` to try it.
+
+Static analysers are also controlling the code. [PHPStan](https://github.com/phpstan/phpstan) and
+[PSalm](https://github.com/vimeo/psalm) are enabled to their maximum level.
+
+[PHP Insights](https://packagist.org/packages/nunomaduro/phpinsights) is also launched in Github actions just for
+information. (_[example of PHP Insights report](https://github.com/loophp/collection/runs/818917887?check_suite_focus=true#step:11:221), you must be logged on Github to see it_)
 
 ## Contributing
 
-Feel free to contribute to this library by sending Github pull requests. I'm quite reactive :-)
+Feel free to contribute by sending Github pull requests. I'm quite reactive :-)
+
+If you can't contribute to the code, you can also sponsor me on [Github](https://github.com/sponsors/drupol) or
+[Paypal](https://www.paypal.me/drupol).
 
 ## On the internet
 * [Reddit announcement thread](https://www.reddit.com/r/PHP/comments/csxw23/a_stateless_and_modular_collection_class/)

docs/index.rst

@@ -24,17 +24,28 @@ On top of this, this library:
  * fully tested,
  * framework agnostic.
 
-Except a few methods, most of methods are `pure`_ and return a new Collection object.
+Except a few methods, most methods are `pure`_ and return a `new Collection object`_.
 
-This library has been inspired by the `Laravel Support Package`_, `Lazy.js`_ and `Ruby arrays`_.
+This library has been inspired by:
+* `Laravel Support Package`_
+* `Lazy.js`_
+* `Ruby Array`_
+* `mtdowling/transducers`_
+
+Similar libraries:
+* `DusanKasan/Knapsack`_
+* `nikic/iter`_
 
 It uses the following `PHP Standards Recommendations`_ :
 
 -  `PSR-4`_ for classes auto loading,
 -  `PSR-12`_ for coding standards.
 
-This library is framework agnostic and can be integrated in any PHP project, in any framework.
-
+.. _nikic/iter: https://github.com/nikic/iter
+.. _DusanKasan/Knapsack: https://github.com/DusanKasan/Knapsack
+.. _mtdowling/transducers: https://github.com/mtdowling/transducers.php
+.. _Ruby Array: https://ruby-doc.org/core-2.7.0/Array.html
+.. _new Collection object: https://github.com/loophp/collection/blob/master/src/Collection.php
 .. _Lazy.js: http://danieltao.com/lazy.js/
 .. _Laravel Support Package: https://github.com/illuminate/support
 .. _pure: https://en.wikipedia.org/wiki/Pure_function