Improve some docs wording

docs/writing-exts.rst

@@ -44,8 +44,8 @@ an `InvalidConfigError`.
 
 Callables can resolve password fields by passing them to `resolve_password()`
 or by using pydantic and the `Password` type.  Callables should resolve paths
-relative to ``configpath`` by using `resolve_path()` or by using pydantic and
-the `Path`, `FilePath`, and/or `DirectoryPath` types.
+relative to the directory containing ``configpath`` by using `resolve_path()`
+or by using pydantic and the `Path`, `FilePath`, and/or `DirectoryPath` types.
 
 The last step of writing a sending method is to package it in a Python project
 and declare the callable as an entry point in the ``outgoing.senders`` entry

src/outgoing/config.py

@@ -18,8 +18,9 @@ class Path(pathlib.Path):
         Converts its input to `pathlib.Path` instances, including expanding
         tildes.  If there is a field named ``configpath`` declared before the
         `Path` field and its value is non-`None`, then the value of the `Path`
-        field will be resolved relative to the ``configpath`` field; otherwise,
-        it will be resolved relative to the current directory.
+        field will be resolved relative to the parent directory of the
+        ``configpath`` field; otherwise, it will be resolved relative to the
+        current directory.
         """
 
         @classmethod

src/outgoing/util.py

@@ -53,9 +53,9 @@ def resolve_path(path: AnyPath, basepath: Optional[AnyPath] = None) -> Path:
     """
     Convert a path to a `pathlib.Path` instance and resolve it using the same
     rules for as paths in ``outgoing`` configuration files: expand tildes by
-    calling `Path.expanduser()`, prepend ``basepath`` (usually the value of
-    ``configpath``) to the path if given, and then resolve the resulting path
-    to make it absolute.
+    calling `Path.expanduser()`, prepend the parent directory of ``basepath``
+    (usually the value of ``configpath``) to the path if given, and then
+    resolve the resulting path to make it absolute.
 
     :param path path: the path to resolve
     :param path basepath: an optional path to resolve ``path`` relative to