doc: add parse stream example

docs/source/getting_started.rst

@@ -33,7 +33,8 @@ A TextGrid is hierarchical structured. It contains one or more tiers, which at t
 Reading a TextGrid file
 -----------------------
 
-To read a TextGrid file you can use the function ``mytextgrid.read_from_file()``. This returns a ``TextGrid`` object.
+To read a TextGrid file you can use the function ``mytextgrid.read_from_file()``.
+This returns a ``TextGrid`` object.
 
 .. code-block:: python
 
@@ -42,6 +43,22 @@ To read a TextGrid file you can use the function ``mytextgrid.read_from_file()``
    >>> path = r'C:\Users\rolan\Documents\projects\sentence1.TextGrid'
    >>> tg = mytextgrid.read_from_file(path)
 
+You can also use ``mytextgrid.read_from_stream()`` which accepts a `str` or
+file-like object.
+
+.. code-block:: python
+
+   >>> import mytextgrid
+
+   >>> path = r'C:\Users\rolan\Documents\projects\sentence1.TextGrid'
+
+   >>> with open(textgrid_path, encoding = 'utf-8') as textfile:
+   >>>      tg = mytextgrid.read_from_stream(textfile)
+
+   >>> with open(textgrid_path, encoding = 'utf-8') as textfile:
+   >>>      text = textfile.read()
+   >>>      tg = mytextgrid.read_from_stream(text)
+
 .. warning::
 
    TextGrid files come in `three formats`_: long, short and binary. At this moment, only the long format is supported.