PG-1127 Rewamp HA solution (17)

* Reworked the overview
* Split setup into individual component pages
* Reworked the intro
* Added diagrams to overview
* Moved components interaction to a separate page
* Reworked initial setup doc
* Moved install steps to every component's page
* Added requirement for redundancy for HAProxy
* Updated how components work together
* Patroni and pgBackRest config'
* Fixed commands, added disclaimer about datadir cleanup for Patroni
* keepalived setup
* Updated images, architecture with 2 types of diagrams, added watchdog component
* Added a redundancy for pgbackrest disclaimer


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Signed-off-by: Anastasia Alexadrova <[email protected]>

Author: nastena1606

docs/_images/PPG_links.png

@@ -144,6 +144,16 @@
     --md-typeset-table-color: hsla(var(--md-hue),0%,100%,0.25)
 }
 
+[data-md-color-scheme="percona-light"] img[src$="#only-dark"],
+[data-md-color-scheme="percona-light"] img[src$="#gh-dark-mode-only"] {
+  display: none; /* Hide dark images in light mode */
+}
+
+[data-md-color-scheme="percona-dark"] img[src$="#only-light"],
+[data-md-color-scheme="percona-dark"] img[src$="#gh-light-mode-only"] {
+  display: none; /* Hide light images in dark mode */
+}
+
 /* Typography */
 
 .md-typeset {