Make instructions to install "requests" more visible in the docs

Instructions explaining that the "requests" library is required and must
be installed separately were not noticeable enough. This moves the
instruction to a new paragraph to make them more evident.

Fix #119

examples/README.txt

@@ -4,7 +4,12 @@
 Examples
 ========
 
-End-to-end examples show how to use PyRocky. You can download these examples as Python files or Jupyter notebooks
-and run them locally. Make sure to add 'requests' library to your environment (`pip install requests`) in order to
-download examples data at runtime.
+End-to-end examples show how to use PyRocky. You can download these examples as Python files or
+Jupyter notebooks and run them locally.
+
+Ensure that the **requests** library is installed in your Python environment in order to download
+examples data at runtime::
+
+    pip install requests
+