[BSv5] More utility updates

[chalin]

• Contributes to Upgrade to Bootstrap 5.2 #470
• Renamed .float-left and .float-right to .float-start and .float-end.
• Renamed .ml-* and .mr-* to .ms-* and .me-* (remaining instances).
• Renamed .pl-* and .pr-* to .ps-* and .pe-*.
• Renamed .text-left and .text-right to .text-start and .text-end, except as noted below.

Preview: https://deploy-preview-1361--docsydocs.netlify.app/

---

Note: I've left out the following text-* change from the footer because the flex boxes aren't working for some reason, and so the first "developer" icon moves off of the page. I'll fix that separately.

diff --git a/layouts/partials/footer.html b/layouts/partials/footer.html
index 00485a5..a95bdad 100644
--- a/layouts/partials/footer.html
+++ b/layouts/partials/footer.html
@@ -4,14 +4,14 @@
     <div class="row">
       <div class="col-6 col-sm-4 text-xs-center order-sm-2">
         {{ with $links }}
-        {{ with index . "user"}}
+        {{ with index . "user" }}
         {{ template "footer-links-block"  . }}
         {{ end }}
         {{ end }}
       </div>
-      <div class="col-6 col-sm-4 text-right text-xs-center order-sm-3">
+      <div class="col-6 col-sm-4 text-end text-xs-center order-sm-3">
         {{ with $links }}
-        {{ with index . "developer"}}
+        {{ with index . "developer" }}
         {{ template "footer-links-block"  . }}
         {{ end }}
         {{ end }}

[chalin]

Note: I've left out the following text-* change from the footer because the flex boxes aren't working for some reason, and so the first "developer" icon moves off of the page. I'll fix that separately.

This will be tracked via:

• [BSv5] Footer updates are necessary #1364