[Update] empennage design documentation

Description

Update of empennage design documentation

docs/documentation/sizing/empennage_design/basic-concepts.md

@@ -2,31 +2,32 @@
 
 Designing an empennage for an aircraft is a challenging tasks. This topic provides basic information for empennages.
 
-If you are already familiar with the basic concepts, you can move on to the [Getting Started](getting-started.md).
+If you are already familiar with the basic concepts, you can move on to the [:octicons-arrow-right-16: Getting Started](getting-started.md).
 
 
 ### Available configurations
 Here you can find available empennage build methods from the _empennage\_design_ tool inside UNICADO.
+
 - _UNICADO is shipped natively with a conventional method for a tube and wing configuration._
 - _A basic Blended Wing body experimental method called vertical\_tails!_
 
-<pre class="mermaid">
+```mermaid
   graph LR;
     A[Empennage Design] -->B[Tube and Wing];
     B-->C[Conventional]
     B-->F[T-Tail]
     A-->D[Blended Wing body]
     D-->H[Vertical Tails]
-</pre>
+```
+
+!!! danger "Important"
+    Since the documentation might be delayed to the development progress - this graph might not have all information yet.
 
-<dl class="section bug">
-<dt>Important</dt>
-<dd>Since the documentation might be delayed to the development progress - this graph might not have all information yet</dd>
-</dl>
 ___
 
 ### Empennage Geometry
 Understanding the empennage geometry is an essential part. Below are key terms and their meanings:
+
 - Aspect Ratio (AR): The ratio of the span to the average chord length
   - _AR = b&sup2; / S_
   - _b : span_
@@ -49,6 +50,7 @@ Understanding the empennage geometry is an essential part. Below are key terms a
 
 ### Airfoil selection
 An airfoil defines the cross-sectional shape of an aerodynamic surface. The key characteristics include:
+
 - Camber: Airfoil curvature
   - _High camber  - generates more lift but comes with increased drag_
   - _No camber (symmetrical) often used for empennages_
@@ -58,4 +60,5 @@ An airfoil defines the cross-sectional shape of an aerodynamic surface. The key
 
 ### Spar Placements
 Spars are the one of the main structural elements inside the empennage to provide strength and rigidity
-  - _Has effects on the control surface sizes_
+
+- _Has effects on the control surface sizes_