docs: minor improved examples

docs/examples.rst

@@ -10,4 +10,16 @@ To see example output without running the commands yourself, check out the :ref:
 
     gptme 'write a web app to particles.html which shows off an impressive and colorful particle effect using three.js'
     gptme 'render mandelbrot set to mandelbrot.png'
+
+    # stdin
+    make test | gptme 'fix the failing tests'
+
+    # from a file
+    gptme 'summarize this' README.md
+    gptme 'refactor this' main.py
+
+    # it can read files using tools, if contents not provided in prompt
     gptme 'suggest improvements to my vimrc'
+
+
+Do you have a cool example? Share it with us in the `Discussions <https://github.com/ErikBjare/gptme/discussions>`_!