make sure __init__ of writers is documented

src/osmium/_osmium.pyi

@@ -121,7 +121,7 @@ class SimpleWriter:
 
         The writer writes out the objects in the order it receives them.
         It is the responsibility of the caller to ensure to follow the
-        [ordering conventions][the-order-of-osm-files]
+        [ordering conventions][order-in-osm-files]
         for OSM files.
 
         The SimpleWriter should normally used as a context manager. If you
@@ -278,7 +278,7 @@ class IdTracker:
             The function scans through the reference file `filename`, finds
             all the objects this tracker references and applies `add_references()`
             to them. The reference file is expected to be
-            [sorted][the-order-of-osm-files].
+            [sorted][order-in-osm-files].
 
             The _relation_depth_ parameter controls how nested relations are
             handled. When set to 0 then only way and node references of

src/osmium/back_reference_writer.py

@@ -21,27 +21,29 @@ class BackReferenceWriter:
         is closed, it writes the final file, mixing together the referenced
         objects from the original file and the written data.
 
-        `outfile` is the name of the output file to write. The file must
-        not yet exist unless `overwrite` is set to True.
-
-        `ref_src` is the OSM input file, where to take the reference objects
-        from. This is usually the same file the data to be written is taken
-        from.
-
-        The writer will by default remove all tags from referenced objects,
-        so that they do not appear as stray objects in the file. Set
-        `remove_tags` to False to keep the tags.
-
-        The writer will not complete nested relations by default. If you
-        need nested relations, set `relation_depth` to the minimum depth
-        to which relations shall be completed.
-
         The writer should usually be used as a context manager.
     """
 
     def __init__(self, outfile: str, ref_src: str,
                  overwrite: bool=False, remove_tags: bool=True,
                  relation_depth: int = 0):
+        """ Create a new writer.
+
+            `outfile` is the name of the output file to write. The file must
+            not yet exist unless `overwrite` is set to True.
+
+            `ref_src` is the OSM input file, where to take the reference objects
+            from. This is usually the same file the data to be written is taken
+            from.
+
+            The writer will by default remove all tags from referenced objects,
+            so that they do not appear as stray objects in the file. Set
+            `remove_tags` to False to keep the tags.
+
+            The writer will not complete nested relations by default. If you
+            need nested relations, set `relation_depth` to the minimum depth
+            to which relations shall be completed.
+        """
         self.outfile = outfile
         self.tmpdir = TemporaryDirectory()
         self.writer = SimpleWriter(str(Path(self.tmpdir.name, 'back_writer.osm.pbf')))

src/osmium/forward_reference_writer.py

@@ -22,28 +22,30 @@ class ForwardReferenceWriter:
         writer is closed, the references are collected from the reference file
         and written out together with the collected data into the final file.
 
-        `outfile` is the name of the output file to write. The file must
-        not yet exist unless `overwrite` is set to True.
-
-        `ref_src` is the OSM input file, where to take the reference objects
-        from. This is usually the same file the data to be written is taken
-        from.
-
-        The writer will collect back references by default to make the
-        file reference-complete. Set `back_references=False` to disable
-        this behaviour.
-
-        The writer will not complete nested relations by default. If you
-        need nested relations, set `relation_depth` to the minimum depth
-        to which relations shall be completed.
-
         The writer should usually be used as a context manager.
     """
 
     def __init__(self, outfile: str, ref_src: str,
                  overwrite: bool=False, back_references: bool=True,
                  remove_tags: bool=True, forward_relation_depth: int=0,
                  backward_relation_depth: int=1) -> None:
+        """ Create a new writer.
+
+            `outfile` is the name of the output file to write. The file must
+            not yet exist unless `overwrite` is set to True.
+
+            `ref_src` is the OSM input file, where to take the reference objects
+            from. This is usually the same file the data to be written is taken
+            from.
+
+            The writer will collect back-references by default to make the
+            file reference-complete. Set `back_references=False` to disable
+            this behaviour.
+
+            The writer will not complete nested relations by default. If you
+            need nested relations, set `relation_depth` to the minimum depth
+            to which relations shall be completed.
+        """
         self.outfile = outfile
         self.tmpdir: Optional['TemporaryDirectory[Any]'] = TemporaryDirectory()
         self.writer = SimpleWriter(str(Path(self.tmpdir.name, 'forward_writer.osm.pbf')))