Fixed some external links in the RST (#4190)

Fix some external links

peps/pep-0694.rst

@@ -138,7 +138,7 @@ methods.
 Upload 2.0 API Specification
 ============================
 
-This PEP draws inspiration from the `Resumable Uploads for HTTP <ietf-draft>`_ internet draft,
+This PEP draws inspiration from the `Resumable Uploads for HTTP <ietf-draft_>`_ internet draft,
 however there are significant differences.  This is largely due to the unique nature of Python
 package releases (i.e. metadata, multiple related artifacts, etc.), and the support for an upload
 session and release stages.  Where it makes sense to adopt details of the draft, this PEP does so.
@@ -413,8 +413,8 @@ the ``files`` mapping, with the above ``Location`` URL included in under the ``l
 
 .. IMPORTANT::
 
-   The `IETF draft <ietf-draft>`_ calls this the URL of the `upload resource
-   <ietf-upload-resource>`_, and this PEP uses that nomenclature as well.
+   The `IETF draft <ietf-draft_>`_ calls this the URL of the `upload resource
+   <ietf-upload-resource_>`_, and this PEP uses that nomenclature as well.
 
 .. _ietf-upload-resource: https://www.ietf.org/archive/id/draft-ietf-httpbis-resumable-upload-05.html#name-upload-creation-2
 
@@ -430,9 +430,9 @@ for "chunked" upload where the file contents are split into multiple requests, a
 
 .. IMPORTANT::
 
-   The protocol defined in this PEP differs from the `IETF draft <ietf-draft>`_ in a few ways:
+   The protocol defined in this PEP differs from the `IETF draft <ietf-draft_>`_ in a few ways:
 
-   * For chunked uploads, the `second and subsequent chunks <ietf-upload-append>`_ are uploaded
+   * For chunked uploads, the `second and subsequent chunks <ietf-upload-append_>`_ are uploaded
      using a ``POST`` request instead of ``PATCH`` requests.  Similarly, this PEP uses
      ``application/octet-stream`` for the ``Content-Type`` headers for all chunks.
 
@@ -892,7 +892,7 @@ Is this Resumable Upload protocol based on anything?
 
 Yes!
 
-It's actually based on the protocol specified in an `active internet draft <ietf-draft>`_, where the
+It's actually based on the protocol specified in an `active internet draft <ietf-draft_>`_, where the
 authors took what they learned implementing `tus <https://tus.io/>`_ to provide the idea of
 resumable uploads in a wholly generic, standards based way.
 
@@ -936,7 +936,7 @@ Open Questions
 Multipart Uploads vs tus
 ------------------------
 
-This PEP currently bases the actual uploading of files on an `internet draft <ietf-draft>`_
+This PEP currently bases the actual uploading of files on an `internet draft <ietf-draft_>`_
 (originally designed by `tus.io <https://tus.io/>`__) that supports resumable file uploads.
 
 That protocol requires a few things: