Update slate bot configs. Add .nvmrc

Author: danielcaldas

.github/stale.yml

@@ -1,15 +1,19 @@
 # https://github.com/apps/stale
 daysUntilStale: 60
-daysUntilClose: 90
+daysUntilClose: 65
 exemptLabels:
   - pinned
   - security
   - bug
   - "in progress"
   - "good first issue"
+  - "help wanted"
+  - "priority low"
+  - "priority normal"
+  - "priority high"
 staleLabel: wontfix
 markComment: >
   This issue has been automatically marked as stale because it has not had
   recent activity. It will be closed if no further activity occurs. Thank you
   for your contributions.
-closeComment: false
+closeComment: false

.nvmrc

@@ -0,0 +1 @@
+12.13.0