PS-10090 [Docs] - Update index 8.4

	new file:   db_terms.txt
	new file:   docs/index-keywords.md
	new file:   generate_index_keywords.py

Author: patrickbirch

db_terms.txt

@@ -0,0 +1,58 @@
+InnoDB
+GTID
+xtrabackup
+percona
+utf8mb4
+sha256
+UUID
+wsrep
+sql_mode
+binlog
+replication
+transaction
+mysql
+cluster
+backup
+restore
+redo
+undo
+snapshot
+lock
+index
+buffer
+cache
+binlog
+DDL
+DML
+row
+table
+column
+schema
+user
+privilege
+query
+join
+view
+trigger
+event
+plugin
+thread
+performance
+connection
+timeout
+error
+log
+binary
+compression
+encryption
+authentication
+authorization
+SSL
+TLS
+audit
+monitoring
+tech preview
+storage engine
+engine
+XtraDB
+LSN