DOC/installation guide: Fix links to examples (#3586)

Author: yvonnefroehlich

doc/install.md

@@ -57,8 +57,8 @@ import pygmt
 pygmt.show_versions()
 ```
 
-You are now ready to make your first figure! Start by looking at our [Intro](examples/intro/index.rst),
-[Tutorials](examples/tutorials/index.rst), and [Gallery](examples/gallery/index.rst). Good luck!
+You are now ready to make your first figure! Start by looking at our [Intro](intro/index.rst),
+[Tutorials](tutorials/index.rst), and [Gallery](gallery/index.rst). Good luck!
 
 :::{note}
 The sections below provide more detailed, step by step instructions to install and test