adding database titles in 2023 README file

Author: dbafromthecold

2023.md

@@ -126,13 +126,13 @@ Or contact us via Twitter, my handle is [@MichaelCade1](https://twitter.com/Mich
 
 ### Databases
 
-- [] 🛢 63 > [](2023/day63.md)
-- [] 🛢 64 > [](2023/day64.md)
-- [] 🛢 65 > [](2023/day65.md)
-- [] 🛢 66 > [](2023/day66.md)
-- [] 🛢 67 > [](2023/day67.md)
-- [] 🛢 68 > [](2023/day68.md)
-- [] 🛢 69 > [](2023/day69.md)
+- [] 🛢 63 > [An introduction to databases](2023/day63.md)
+- [] 🛢 64 > [Querying data in databases](2023/day64.md)
+- [] 🛢 65 > [Backing up and restoring databases](2023/day65.md)
+- [] 🛢 66 > [High availability and disaster recovery](2023/day66.md)
+- [] 🛢 67 > [Performance tuning](2023/day67.md)
+- [] 🛢 68 > [Database security](2023/day68.md)
+- [] 🛢 69 > [Monitoring and troubleshooting database issues](2023/day69.md)
 
 ### Serverless