docs: make monitoring "phases" table titles consistent

Reported-by: Nitin Jadhav

Discussion: https://postgr.es/m/CAMm1aWbmTHwHKC2PERH0CCaFVPoxrtLeS8=wNuoge94qdSp3vA@mail.gmail.com

Author: Nitin Jadhav

Backpatch-through: 13

Author: bmomjian

doc/src/sgml/monitoring.sgml

@@ -5894,7 +5894,7 @@ SELECT pg_stat_get_backend_pid(s.backendid) AS pid,
   </table>
 
   <table id="analyze-phases">
-   <title>ANALYZE phases</title>
+   <title>ANALYZE Phases</title>
    <tgroup cols="2">
     <colspec colname="col1" colwidth="1*"/>
     <colspec colname="col2" colwidth="2*"/>
@@ -6824,7 +6824,7 @@ SELECT pg_stat_get_backend_pid(s.backendid) AS pid,
   </table>
 
   <table id="basebackup-phases">
-   <title>Base backup phases</title>
+   <title>Base Backup Phases</title>
    <tgroup cols="2">
     <colspec colname="col1" colwidth="1*"/>
     <colspec colname="col2" colwidth="2*"/>