Using http secure protocol where we can

docs/CONTRIBUTING.md

@@ -190,4 +190,4 @@ If you plan to make significant or breaking changes, please open an issue so we
 
 Thanks to the Pharo team for all their dedication in building a modern open source Smalltalk.
 
-![Pharo](http://pharo.org/web/files/pharo.png)
+![Pharo](https://pharo.org/web/files/pharo.png)

docs/LEARNING.md

@@ -4,23 +4,23 @@ As Smalltalk is widely used, there is rich choice of reading material.
 
 ## Starting Out
 
-* [Pharo Main Site](http://pharo.org/documentation):
+* [Pharo Main Site](https://pharo.org/documentation):
 has a wealth of articles and help
-* [Pharo Syntax Cheatsheet](http://files.pharo.org/media/pharoCheatSheet.pdf):
+* [Pharo Syntax Cheatsheet](https://files.pharo.org/media/pharoCheatSheet.pdf):
 it fits on a postcard
-* [I Can Read C but not Smalltalk](http://www.eli.sdsu.edu/courses/spring01/cs635/readingSmalltalk.pdf): several easy steps to understanding Smalltalk
+* [I Can Read C but not Smalltalk](https://www.eli.sdsu.edu/courses/spring01/cs635/readingSmalltalk.pdf): several easy steps to understanding Smalltalk
 * [Pharo By Example (9.0)](https://books.pharo.org/pharo-by-example9/):
 a full pdf book with step by step examples
-* [Learning OOP and TDD in Pharo](http://books.pharo.org/learning-oop/):
+* [Learning OOP and TDD in Pharo](https://books.pharo.org/learning-oop/):
 introduces more programming techniques and concepts
 * [Discord](https://discord.gg/QewZMZa) has an
-active online Pharo discussions forum (use the invite link at the top of the [Community Page](http://pharo.org/community))
-* [Pharo Mooc](http://mooc.pharo.org/):
+active online Pharo discussions forum (use the invite link at the top of the [Community Page](https://pharo.org/community))
+* [Pharo Mooc](https://mooc.pharo.org/):
 provides a series of full programming courses and videos
 
 ## More Advanced
 
-* [Deep Into Pharo](http://books.pharo.org/deep-into-pharo/):
+* [Deep Into Pharo](https://books.pharo.org/deep-into-pharo/):
 takes you through more advanced topics like graphics and parsing
 * [Pharo with style](https://github.com/SquareBracketAssociates/Booklet-PharoWithStyle):
 is the guide for formatting and designing the Pharo way

docs/RESOURCES.md

@@ -20,7 +20,7 @@ The following are useful starting points for getting more detailed information a
 ### Docs
 
 * [Pharo with style](https://github.com/SquareBracketAssociates/Booklet-PharoWithStyle)
-* [Smalltalk with style](http://sdmeta.gforge.inria.fr/FreeBooks/WithStyle/SmalltalkWithStyle.pdf)
+* [Smalltalk with style](https://web.archive.org/web/20200215093658/http://sdmeta.gforge.inria.fr/FreeBooks/WithStyle/SmalltalkWithStyle.pdf)
 * [Smalltalk ANSI Standard](http://wiki.squeak.org/squeak/uploads/172/standard_v1_9-indexed.pdf)
 * [Smalltalk Grammar](https://gist.github.com/sin3141592/602700)
 * [Deep Into Pharo](http://books.pharo.org/deep-into-pharo/)