docs: remove section titles from multiple documentation files for consistency

Author: HarrisonKramer

docs/api.rst

@@ -1,6 +1,3 @@
-Optiland API
-============
-
 This section contains the API reference documentation for Optiland.
 
 .. toctree::

docs/contributing.rst

@@ -1,6 +1,3 @@
-Contributing
-============
-
 .. _contributing:
 
 Thank you for your interest in contributing to **Optiland**! Contributions are welcome in many forms, including but not limited to:

docs/developers_guide.rst

@@ -1,8 +1,5 @@
 .. _developers_guide:
 
-Developer's Guide
-=================
-
 .. image:: images/developers_guide.png
    :align: center
 

docs/example_gallery.rst

@@ -1,8 +1,5 @@
 .. _example_gallery:
 
-Optiland Gallery
-================
-
 This gallery contains a collection of examples demonstrating the capabilities of Optiland. Each example is a self-contained Jupyter notebook that shows how to achieve a specific task using Optiland. The examples cover a wide range of topics, from basic lens design to freeform optics.
 
 .. toctree::

docs/learning_guide.rst

@@ -1,8 +1,5 @@
 .. _learning_guide:
 
-Optiland Learning Guide
-=======================
-
 This learning guide breaks down Optiland into a series of tutorials that cover the basic concepts and functionalities of the package. Each tutorial is a self-contained Jupyter notebook that demonstrates how to perform a specific task using Optiland. The tutorials are designed to be followed sequentially, starting with an introduction to Optiland and progressing to more advanced topics.
 
 

docs/license.rst

@@ -1,5 +1,5 @@
-License
-=======
+MIT License
+-----------
 
 .. _license: