docs: update README to include nightly releases (#384)

Drew Smirnoff created

Change summary

README.md | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

Detailed changes

README.md 🔗 

@@ -14,9 +14,15 @@
 [![Go Reference](https://pkg.go.dev/badge/github.com/floatpane/matcha.svg)](https://pkg.go.dev/github.com/floatpane/matcha)
 [![Awesome](https://awesome.re/badge.svg)](https://github.com/rothgar/awesome-tuis#messaging)
 
+
+</div> 
+
+> [!TIP]
+> There are [nightly releases](https://github.com/floatpane/matcha/releases/tag/nightly)!
+
 **A powerful, feature-rich email client for your terminal.** Built with Go and the Bubble Tea TUI framework, Matcha brings a beautiful, modern email experience to the command line with support for rich content, multiple accounts, and advanced terminal features.
 
-</div>
+