Add Rplots.pdf and *.tbi to .gitignore

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: bschilder

.gitignore

@@ -40,4 +40,6 @@ vignettes/*.R
 *.utf8.md
 *.knit.md
 # R Environment Variables
-.Renviron 
+.Renviron
+*.tbi
+Rplots.pdf