[REFACTOR] Updated wing design and c++ modularization doc and added new documentation for airfoils and endnode + placeholder for pyavl- and pyavlunicadopackage

Description

Refactored and added different documentations to the documentation page

Related Issue(s)

• Closes #27 (closed)

Other Changes

• N.A.

Screenshots/Logs

Testing Instructions

1. [Step 1: Checkout branch]
2. [Step 2: Run mkdocs serve + have a look at documentation for modularization description, wing design, airfoils lib, and endnode.h + index page for libraries documentation]

Developer Checklist

• Code has been tested locally and/or in pipeline.
• (if applicable) documentation updated.
• (if applicable) impact of new dependencies reviewed and included in project.
• Merge conflicts resolved with the target branch.

Additional Notes

• N.A.

docs/documentation/libraries/airfoils/index.md

+# The `Airfoils` library
+
+**Description:**
+This file is part of UNICADO. It implements the `Airfoils` class which manages airfoil data stored in files. The class provides functionality to load airfoil files from a specified directory, print the available airfoils, retrieve airfoil polygon data, and copy airfoil files to a target directory.
+
+---
+
+## Class: Airfoils
+
+### Overview
+- **Purpose:** Manages airfoil data by loading airfoil files from a directory and providing methods to interact with them.
+- **Key Responsibilities:**
+    - Load airfoil data from a given directory.
+    - Maintain a collection (`available_airfoils`) that maps airfoil names to their file paths.
+    - Provide methods to print, retrieve, and copy airfoil data.
+
+---
+
+### Constructor
+
+#### `Airfoils(const std::filesystem::path& path_to_airfoil_directory)`
+- **Description:** Initializes the `Airfoils` object by loading airfoil files from the provided directory.
+- **Parameters:**
+    - `path_to_airfoil_directory`: Filesystem path to the directory containing airfoil files.
+- **Behavior:**
+    - Checks if the provided directory exists.
+    - If not, throws an error using `throwError` with a formatted message.
+    - Calls the private method `add_directory_airfoils(path_to_airfoil_directory)` to populate the `available_airfoils` map.
+
+---
+
+### Public Methods
+
+#### `void print_available_airfoils()`
+- **Description:** Prints the list of available airfoils with their names and file paths.
+- **Behavior:**
+    - Iterates over the `available_airfoils` map and prints each entry using formatted output.
+    - Uses `std::cout` or a runtime logging stream (`myRuntimeInfo->out`) if available.
+
+---
+
+#### `geom2::Polygon_2 get_airfoil(const std::string& airfoil)`
+- **Description:** Retrieves the polygon data of the specified airfoil.
+- **Parameters:**
+    - `airfoil`: Name of the airfoil.
+- **Return:**
+    - A `geom2::Polygon_2` object representing the airfoil's polygon data.
+- **Behavior:**
+    - Searches for the airfoil in the `available_airfoils` map.
+    - If the airfoil is not found, throws an error.
+    - Otherwise, reads and returns the airfoil data using `geom2::io::read_airfoil`.
+
+---
+
+#### `void copy_available_airfoil(const std::string& airfoil, const std::filesystem::path& target_directory)`
+- **Description:** Copies the specified airfoil file to a target directory.
+- **Parameters:**
+    - `airfoil`: Name of the airfoil.
+    - `target_directory`: Filesystem path to the destination directory.
+- **Behavior:**
+    - Checks if the target directory exists; if not, throws an error.
+    - Validates that the airfoil is available in the `available_airfoils` map; if not, throws an error.
+    - Compares the absolute paths of the source (airfoil file) and the target directory.
+        - If they are the same, logs that the copying is skipped.
+    - Attempts to copy the airfoil file using `std::filesystem::copy` with the `update_existing` option.
+    - Catches any exceptions during copying and rethrows them using `throwError`.
+
+---
+
+### Private Methods
+
+#### `void add_directory_airfoils(const std::filesystem::path& path_to_airfoil_directory)`
+- **Description:** Adds all airfoil files from the specified directory to the `available_airfoils` map.
+- **Parameters:**
+    - `path_to_airfoil_directory`: Filesystem path to the directory containing airfoil files.
+- **Behavior:**
+    - Verifies that the directory exists; if not, throws an error.
+    - Iterates over each entry in the directory using `std::filesystem::directory_iterator`.
+    - For each entry, calls the private method `add_airfoil(entry.path())`.
+
+---
+
+#### `void add_airfoil(const std::filesystem::path& airfoil_path)`
+- **Description:** Adds a single airfoil file to the `available_airfoils` map.
+- **Parameters:**
+    - `airfoil_path`: Filesystem path to the airfoil file.
+- **Behavior:**
+    - Checks if the file exists; if not, throws an error.
+    - Verifies that the path is a regular file and has a `.dat` extension.
+    - Extracts the airfoil name (using the filename's stem) and inserts it into the `available_airfoils` map.
+
+---