Document the option to name the configuration file towncrier.toml

Remove obsolete reference to towncrier.ini.

README.rst

@@ -35,7 +35,7 @@ Install from PyPI::
    It is usable by projects written in other languages, provided you give it the version of the project when invoking it.
    For Python 2/3 compatible projects, the version can be discovered automatically.
 
-In your project root, add a ``pyproject.toml`` file.
+In your project root, add a ``towncrier.toml`` or a ``pyproject.toml`` file (if both files exist, the first will take precedence).
 You can configure your project in two ways.
 To configure it via an explicit directory, add:
 
@@ -84,7 +84,7 @@ To produce the news file for real, run::
 
     towncrier build
 
-This command will remove the news files (with ``git rm``) and append the built news to the filename specified in ``towncrier.ini``, and then stage the news file changes (with ``git add``).
+This command will remove the news files (with ``git rm``) and append the built news to the filename specified by ``filename`` configuration option, and then stage the news file changes (with ``git add``).
 It leaves committing the changes up to the user.
 
 If you wish to have content at the top of the news file (for example, to say where you can find the tickets), put your text above a rST comment that says::

src/towncrier/newsfragments/172.doc.rst

@@ -0,0 +1,2 @@
+The README now mentions the possibility to name the configuration file
+``towncrier.toml`` (in addition to ``pyproject.toml``).