README: fix links

README.md

@@ -8,38 +8,38 @@ Contents of this repository are based on [Ruby programming course material](http
 
 ## Contents
 
-- [Fundamentals](src/branch/master/1_fundamentals)
+- [Fundamentals](1_fundamentals)
 
     - Description: Ruby syntax and basic methods
 
-- [Data types](src/branch/master/2_datatypes)
+- [Data types](2_datatypes)
 
     - Description: Different datatypes in Ruby
 
-- [Logical operators and conditions](src/branch/master/3_logical-operators-and-conditions)
+- [Logical operators and conditions](3_logical-operators-and-conditions)
 
     - Description: `if/else` statements & `case` structure in Ruby
 
-- [Loops](src/branch/master/4_loops)
+- [Loops](4_loops)
 
     - Description: `for`, `while` and `until` loops in Ruby
 
-- [External files](src/branch/master/5_external-files)
+- [External files](5_external-files)
 
     - Description: File operations in Ruby
 
-- [Methods](src/branch/master/6_methods)
+- [Methods](6_methods)
 
     - Description: Custom methods in Ruby
 
-- [Modules](src/branch/master/7_modules)
+- [Modules](7_modules)
 
     - Description: Custom modules in Ruby
 
-- [Errors and exceptions](src/branch/master/8_errors)
+- [Errors and exceptions](8_errors)
 
     - Description: Error and exception handling in Ruby
 
-- [Classes and objects](src/branch/master/9_classes-and-objects)
+- [Classes and objects](9_classes-and-objects)
 
     - Description: Custom classes and objects in Ruby