Lint: Optimize images to reduce file size by 1.5-2x for free (#2542)

* Lint: Optimize images to reduce file size by 25-50% for free

* Lint: Switch PEPs with SVGs over to using them and remove old PNGs

pep-0001.txt

@@ -440,7 +440,7 @@ an API can replace version 1.
 
 The possible paths of the status of PEPs are as follows:
 
-.. image:: pep-0001-process_flow.png
+.. image:: pep-0001/process_flow.svg
    :class: invert-in-dark-mode
    :alt: PEP process flow diagram
 

pep-0495.txt

@@ -384,7 +384,7 @@ smaller after any transition that creates a fold.  The values returned
 by ``tzname()`` and ``dst()`` may or may not depend on the value of
 the ``fold`` attribute depending on the kind of the transition.
 
-.. image:: pep-0495-fold-2.png
+.. image:: pep-0495-fold.svg
   :align: center
   :width: 60%
   :class: invert-in-dark-mode
@@ -410,7 +410,7 @@ local time that falls in a gap, the rules in effect before the
 transition should be used if ``fold=0``.  Otherwise, the rules in
 effect after the transition should be used.
 
-.. image:: pep-0495-gap.png
+.. image:: pep-0495-gap.svg
   :align: center
   :width: 60%
   :class: invert-in-dark-mode