content/web-apis: Fix links, warning about bs4

- Fix to intersphinx links
- Warning that bs4 may not be available

Author: rkdarst

content/web-apis.ipynb

@@ -74,7 +74,7 @@
     "\n",
     "You can even test this in your web browser: <https://catfact.ninja/fact>\n",
     "\n",
-    "Using the Requests library, we do this with {meth}`~requests.get`."
+    "Using the Requests library, we do this with {func}`~requests.get`."
    ]
   },
   {
@@ -192,7 +192,7 @@
    "source": [
     "URLs containing parameters can always be constructed manually using the _&_ character and then listing the parameter (_key_, _value_) pairs as above.\n",
     "\n",
-    "However, _Requests_ allows us to provide the parameters as a dictionary of strings, using the _params_ keyword argument to {meth}`~requests.get`. This is easier to read and less error-prone."
+    "However, _Requests_ allows us to provide the parameters as a dictionary of strings, using the _params_ keyword argument to {func}`~requests.get`. This is easier to read and less error-prone."
    ]
   },
   {
@@ -478,7 +478,7 @@
     "\n",
     ":::{exercise} Exercise WebAPIs-3: Scrape links from a webpage (Advanced)\n",
     "\n",
-    "Let's use _Requests_ to get the HTML source code of www.example.com, examine it, and use the [Beautiful Soup](https://www.crummy.com/software/BeautifulSoup/bs4/doc/) library to extract links from it.\n",
+    "Let's use _Requests_ to get the HTML source code of www.example.com, examine it, and use the [Beautiful Soup](https://www.crummy.com/software/BeautifulSoup/bs4/doc/) library to extract links from it.  **Note:** This requires the extra `bs4` Python package to be installed, which was not in our initial requirements.  Consider this a demo.\n",
     ":::"
    ]
   },