Refactor documentation of extension autoloading

Author: MilesCranmer

docs/src/compat.md

@@ -67,8 +67,9 @@ The `juliacall` IPython extension adds these features to your IPython session:
 
 The extension is experimental and unstable - the API can change at any time.
 
-Enable the extension with `%load_ext juliacall`.
-See [the IPython docs](https://ipython.readthedocs.io/en/stable/config/extensions/).
+You can explicitly enable the extension with `%load_ext juliacall`, but
+it will automatically be loaded if `juliacall` is imported and IPython is detected.
+You can disable this behavior with an [environment variable](@ref julia-config).
 
 The `%%julia` cell magic can synchronise variables between Julia and Python by listing them
 on the first line:
@@ -88,6 +89,9 @@ In [5]: z
 Out[5]: '2^8 = 256'
 ```
 
+Also see [the IPython docs](https://ipython.readthedocs.io/en/stable/config/extensions/)
+for more information on extensions.
+
 ## Asynchronous Julia code (including Makie)
 
 Asynchronous Julia code will not normally run while Python is executing, unless it is in a

docs/src/juliacall.md

@@ -123,3 +123,4 @@ be configured in two ways:
 | `-X juliacall-sysimage=<file>` | `PYTHON_JULIACALL_SYSIMAGE=<file>` | Use the given system image. |
 | `-X juliacall-threads=<N\|auto>` | `PYTHON_JULIACALL_THREADS=<N\|auto>` | Launch N threads. |
 | `-X juliacall-warn-overwrite=<yes\|no>` | `PYTHON_JULIACALL_WARN_OVERWRITE=<yes\|no>` | Enable or disable method overwrite warnings. |
+| `-X juliacall-autoload-ipython-extension=<yes\|no>` | `PYTHON_JULIACALL_AUTOLOAD_IPYTHON_EXTENSION=<yes\|no>` | Enable or disable IPython extension autoloading. |

pysrc/juliacall/__init__.py

@@ -257,11 +257,7 @@ def jlstr(x):
             if CONFIG['autoload_ipython_extension'] is None:
                 # Only let the user know if it was not explicitly set
                 print(
-                    "Detected IPython. Loading juliacall extension. To disable, you can either "
-                    "set the environment variable PYTHON_JULIACALL_AUTOLOAD_IPYTHON_EXTENSION=no or pass the "
-                    "command line argument '-X juliacall-autoload-ipython-extension=no'. Inside Jupyter, you can "
-                    "do this with `import os; os.environ['PYTHON_JULIACALL_AUTOLOAD_IPYTHON_EXTENSION'] = 'no'`. "
-                    "To suppress this message, set PYTHON_JULIACALL_AUTOLOAD_IPYTHON_EXTENSION=yes."
+                    "Detected IPython. Loading juliacall extension. See https://juliapy.github.io/PythonCall.jl/stable/compat/#IPython"
                 )
 
             load_ipython_extension(get_ipython())