docs: Moving learn.md to Philosophy section, to reduce confusion between learn.md and contrib.md

- Relocated src/dev/learn.md to src/philosophy/learn.md
  - Updated SUMMARY.md to place Learn under Philosophy section
  - Updated all learn.md references across the docs

doc/src/SUMMARY.md

@@ -8,6 +8,7 @@
   - [Discussion](philosophy/meetings.md)
   - [Ideology](philosophy/ideology.md)
   - [Books](philosophy/books.md)
+  - [Learn](philosophy/learn.md)
 
 # User Guide
 
@@ -32,7 +33,6 @@
 - [Development](dev/dev.md)
   - [Contribute](dev/contrib/contrib.md)
     - [Using Tor](dev/contrib/tor.md)
-  - [Learn](dev/learn.md)
   - [API Rustdoc](dev/rustdoc.md)
   - [Native Contracts](dev/native_contracts.md)
   - [Seminars](dev/seminars.md)

doc/src/dev/contrib/contrib.md

@@ -15,10 +15,10 @@ identify issues and areas of improvement.
 
 Contribute according to your own interests, skills, and topics in which you would
 like to become more knowledgable. Take initiative. Other darkfi devs can help you
-as mentors: see [the Methodology section of the Study Guide](../learn.md#methodology).
+as mentors: see [the Methodology section of the Study Guide](../philosophy/learn.md#methodology).
 
 Few people are able be an expert in all domains. Choose a topic and specialize.
-Example specializations are described [here](../learn.md#branches).
+Example specializations are described [here](../philosophy/learn.md#branches).
 Don't make the mistake that you must become an expert in all areas before getting started.
 It's best to just jump in.
 

doc/src/dev/contrib/hiring.md

@@ -7,7 +7,7 @@ Follow this guide to work on DarkFi and get paid.
 If you're not a dev, see the [learn] section. We offer mentoring.
 Anybody can become a dev. It's not that hard, you just need focus and dedication.
 
-[learn]: ../learn.md
+[learn]: ../philosophy/learn.md
 
 ## Criteria
 

doc/src/start-here.md

@@ -46,7 +46,7 @@ Check out the [contributor's guide](dev/contrib/contrib.md) for where
 to find tasks and submitting patches to the project.
 
 If you're not a dev but wish to learn then take a look at the
-[agorism hackers study guide](dev/learn.md).
+[agorism hackers study guide](philosophy/learn.md).
 
 Lastly familiarize yourself with the
 [project architecture](arch/arch.md). The book also contains a