Maciejedits: Website feature upgrade and some minor text edits on the mkdocs.yml

Website feature upgrade and some minor text edits on the mkdocs.yml

1. Change the website title to the full name of the course (rephrasing)
2. Change website description (rephrasing)
3. Setting up site search feature (plugin)
4. Setting up navigation feature (theme:feature)
5. Update copyright date (cosmetics)

src/index.md

-# Math for quantum
+# Math for Quantum
 
 !!! summary "Learning goals"
 
@@ -8,20 +8,20 @@
     - solve mathematical problems encountered in the follow-up courses of the minor.
     - explain Hilbert spaces of (in)finite dimension. 
 
-Mathematics for quantum mechanics gives you a compact introduction and review
+*Mathematics for Quantum Mechanics* gives you a compact introduction and review
 of the basic mathematical tools commonly used in quantum mechanics. Throughout
-the course we have kept quantum mechanics applications in mind, but at the
-core this is still a math course. For this reason, applying what you learned
+the course, we keep quantum mechanics applications in mind, but at the
+core, this is still a math course. For this reason, applying what you learned
 to examples and exercises is **crucial**!
 
-Each lecture note comes with an extensive set of exercises. Each exercise is labeled
-according to difficulty:
+Each lecture note comes with an extensive set of exercises, and each exercise is labeled
+according to its difficulty:
 
 - [:grinning:] easy
 - [:smirk:] intermediate
 - [:sweat:] difficult
 
-In these notes our aim is to provide learning materials which are:
+In these notes, our aim is to provide learning materials which are:
 
 - self-contained
 - easy to modify and remix, so we provide the full source, including the code