Rename "Declaring project metadata" to "pyproject.toml specification" to match new content

Adjust references accordingly.

Author: jeanas

source/specifications/index.rst

@@ -19,9 +19,9 @@ Package Distribution Metadata
    core-metadata
    version-specifiers
    dependency-specifiers
-   declaring-project-metadata
    inline-script-metadata
    platform-compatibility-tags
+   pyproject-toml
 
 Package Installation Environment Metadata
 -----------------------------------------

source/specifications/declaring-project-metadata.rst renamed to source/specifications/pyproject-toml.rst

@@ -1,8 +1,8 @@
-.. _declaring-project-metadata:
+.. _pyproject-toml-spec:
 
-==========================
-Declaring project metadata
-==========================
+================================
+``pyproject.toml`` specification
+================================
 
 :pep:`621` specifies how to write a project's
 :ref:`core metadata <core-metadata>` in a ``pyproject.toml`` file for

source/specifications/source-distribution-format.rst

@@ -58,7 +58,7 @@ A ``.tar.gz`` source distribution (sdist) contains a single top-level directory
 called ``{name}-{version}`` (e.g. ``foo-1.0``), containing the source files of
 the package. The name and version MUST match the metadata stored in the file.
 This directory must also contain a :file:`pyproject.toml` in the format defined in
-:ref:`declaring-build-dependencies`, and a ``PKG-INFO`` file containing
+:ref:`pyproject-toml-spec`, and a ``PKG-INFO`` file containing
 metadata in the format described in the :ref:`core-metadata` specification. The
 metadata MUST conform to at least version 2.2 of the metadata specification.