fix typo conf.by -> conf.py

docs/source/sphinx-config.rst

@@ -30,7 +30,7 @@ Continuing, if we want Sphinx to autogenerate documentation from the comments of
     import sys
     sys.path.insert(0, os.path.abspath('../../simpleble/'))
 
-Notice how we altered the path specified in line 3 (highlighted). This is because our ``conf.py`` file is located in ``simpleble-master/docs/source``, while our Python source codes, in this case the file ``simpleble.py``, are located inside ``simpleble-master/simpleble``. This means that when Sphinx is looking for our source codes, it now knows that it must go two directories up from ``conf.by`` (indicated by the ``../../`` part of the absolute path) and inside the folder ``simpleble-master/simpleble``. This is equivalent to adding the directory of our Python source files to PYTHONPATH. 
+Notice how we altered the path specified in line 3 (highlighted). This is because our ``conf.py`` file is located in ``simpleble-master/docs/source``, while our Python source codes, in this case the file ``simpleble.py``, are located inside ``simpleble-master/simpleble``. This means that when Sphinx is looking for our source codes, it now knows that it must go two directories up from ``conf.py`` (indicated by the ``../../`` part of the absolute path) and inside the folder ``simpleble-master/simpleble``. This is equivalent to adding the directory of our Python source files to PYTHONPATH. 
 
 **It is important to note here that the absolute path must be specified in relation to where** ``conf.py`` **resides, i.e. our `Sphinx source root`, rather than in relation to the `Documentation root`**.
 
@@ -53,4 +53,4 @@ Save and close the file (Ctrl+X -> Enter -> Y -> Enter).
 
 Apart from specifying the dependencies of our package, the ``requirements.txt`` file can be used to batch install any such dependencies by calling ``sudo pip install -r requirements.txt``. For more information on requirements files, you can have a look at `pip's documentation <https://pip.pypa.io/en/stable/user_guide/#requirements-files>`_. 
 
-We will later also use the ``requirements.txt`` file when configuring the building process of our ReadTheDocs documentation. If we didn't have the requirements file, then ReadTheDocs would fail to run ``autodoc`` in order to generate our documentation from the comments in our source code. In other words, when building our documentation, RTD calls a ``pip install -r requirements.txt``, which installs any requirements in a virtual environment, which is then where ``sphinx-apidoc`` is run.
+We will later also use the ``requirements.txt`` file when configuring the building process of our ReadTheDocs documentation. If we didn't have the requirements file, then ReadTheDocs would fail to run ``autodoc`` in order to generate our documentation from the comments in our source code. In other words, when building our documentation, RTD calls a ``pip install -r requirements.txt``, which installs any requirements in a virtual environment, which is then where ``sphinx-apidoc`` is run.