docs: cross-page links fixed

docs/getting_started/introduction.md

@@ -26,8 +26,8 @@ errors and debugging as easy and user-friendly as possible.
 To achieve this goal, several techniques are applied:
 
 - usage of C++20 concepts,
-- [using strong types for framework entities (instead of type aliases)](../../users_guide/framework_basics/interface_introduction/#strong-types-instead-of-aliases),
-- [usage of expression templates to improve the readability of generated types](../../users_guide/framework_basics/interface_introduction/#expression-templates),
+- [using strong types for framework entities (instead of type aliases)](../users_guide/framework_basics/interface_introduction.md#strong-types-instead-of-aliases),
+- [usage of expression templates to improve the readability of generated types](../users_guide/framework_basics/interface_introduction.md#expression-templates),
 - limiting the number of template arguments to the bare minimum.
 
 !!! note
@@ -50,27 +50,27 @@ To achieve this goal, several techniques are applied:
 | **Low Standardization Cost** | - Small number of predefined entities needed thanks to composability<br>- No external dependencies (assuming full C++20 support)<br>- No macros in the user interface (besides portability and standard-compliance issues)<br>- Possibility to be standardized as a [freestanding] part of the C++ Standard Library                                 |
 
 
-[The affine space strong types]: ../../users_guide/framework_basics/the_affine_space
-[Compile-time checked conversions of quantities and units]: ../../users_guide/framework_basics/systems_of_quantities/#converting-between-quantities
-[Unique support for many quantities of the same kind]: ../../users_guide/framework_basics/systems_of_quantities/#quantities-of-the-same-kind
-[Type-safe equations on scalar, vector, and tensor quantities and their units]: ../../users_guide/framework_basics/quantity_arithmetics
-[Value-preserving conversions]: ../../users_guide/framework_basics/value_conversions/#value-preserving-conversions
+[The affine space strong types]: ../users_guide/framework_basics/the_affine_space.md
+[Compile-time checked conversions of quantities and units]: ../users_guide/framework_basics/systems_of_quantities.md#converting-between-quantities
+[Unique support for many quantities of the same kind]: ../users_guide/framework_basics/systems_of_quantities.md#quantities-of-the-same-kind
+[Type-safe equations on scalar, vector, and tensor quantities and their units]: ../users_guide/framework_basics/quantity_arithmetics.md
+[Value-preserving conversions]: ../users_guide/framework_basics/value_conversions.md#value-preserving-conversions
 
-[Optimized for readable compilation errors and great debugging experience]: ../../users_guide/framework_basics/simple_and_typed_quantities/#easy-to-understand-compilation-error-messages
-[Efficient and composable way to specify a unit of choice]: ../../users_guide/framework_basics/systems_of_units/#units-compose
-[Value-based dimension, unit, and quantity equations]: ../../users_guide/framework_basics/interface_introduction/#value-based-equations
+[Optimized for readable compilation errors and great debugging experience]: ../users_guide/framework_basics/simple_and_typed_quantities.md#easy-to-understand-compilation-error-messages
+[Efficient and composable way to specify a unit of choice]: ../users_guide/framework_basics/systems_of_units.md#units-compose
+[Value-based dimension, unit, and quantity equations]: ../users_guide/framework_basics/interface_introduction.md#value-based-equations
 
-[Systems of Quantities]: ../../users_guide/framework_basics/systems_of_quantities
-[Systems of Units]: ../../users_guide/framework_basics/systems_of_units
-[Scalar, vector, and tensor quantities]: ../../users_guide/framework_basics/character_of_a_quantity
-[The affine space]: ../../users_guide/framework_basics/the_affine_space
-[Natural units systems support]: ../../users_guide/defining_systems/natural_units
-[Strong angular system]: ../../users_guide/defining_systems/strong_angular_system
-[Supports any unit's magnitude (huge, small, floating-point)]: ../../users_guide/framework_basics/systems_of_units/#scaled-units
-[Faster-than-lightspeed constants]: ../../users_guide/framework_basics/faster_than_lightspeed_constants
-[Highly adjustable text-output formatting]: ../../users_guide/framework_basics/text_output
+[Systems of Quantities]: ../users_guide/framework_basics/systems_of_quantities.md
+[Systems of Units]: ../users_guide/framework_basics/systems_of_units.md
+[Scalar, vector, and tensor quantities]: ../users_guide/framework_basics/character_of_a_quantity.md
+[The affine space]: ../users_guide/framework_basics/the_affine_space.md
+[Natural units systems support]: ../users_guide/defining_systems/natural_units.md
+[Strong angular system]: ../users_guide/defining_systems/strong_angular_system.md
+[Supports any unit's magnitude (huge, small, floating-point)]: ../users_guide/framework_basics/systems_of_units.md#scaled-units
+[Faster-than-lightspeed constants]: ../users_guide/framework_basics/faster_than_lightspeed_constants.md
+[Highly adjustable text-output formatting]: ../users_guide/framework_basics/text_output.md
 
-[Each entity can be defined with a single line of code]: ../../users_guide/framework_basics/interface_introduction/#new-style-of-definitions
-[User can easily extend the systems with custom dimensions, quantities, and units]: ../../users_guide/framework_basics/interface_introduction/#new-style-of-definitions
+[Each entity can be defined with a single line of code]: ../users_guide/framework_basics/interface_introduction.md#new-style-of-definitions
+[User can easily extend the systems with custom dimensions, quantities, and units]: ../users_guide/framework_basics/interface_introduction.md#new-style-of-definitions
 
 [freestanding]: https://en.cppreference.com/w/cpp/freestanding