put file names in backticks, though gitea doesn't handle them..

README.md

@@ -8,9 +8,9 @@ the hash.
 
 There is the concept of aliases to make the import statements easier
 to read.  An alias file is currently limited to python packages (modules
-in a directory w/ an __init__.py file).  An example is the randpkg in
-the fixtures directory.  You can put a file named cas_aliases.txt along
-side the __init__.py file.  Each line of the file is:
+in a directory w/ an `__init__.py` file).  An example is the randpkg in
+the fixtures directory.  You can put a file named `cas_aliases.txt` along
+side the `__init__.py` file.  Each line of the file is:
 ```
 <alias>	<url>
 ```