Update instructions

Author: csexton

README.md

@@ -2,6 +2,26 @@
 
 Interactive debugger for GitHub Actions
 
+## Usage
+
+In the log for the action you will see:
+
+```
+Running tmate...
+
+To connect to this session copy-n-paste the following into a terminal:
+
+ssh redactedMxoJ0pXmjredacted@nyc1.tmate.io
+```
+
+Simply follow the instructions and copy the ssh command into your terminal to create an ssh connection the running instance. The session will close immedeatly after closing the ssh connection to the running instance.
+
+There is a global timeout after 15 minutes. This will close any open ssh sessions. To prevent the session from being terminated run:
+
+```
+touch /tmp/keepalive
+```
+
 ## Acknowledgments
 
 * [tmate.io](https://tmate.io)

script.sh

@@ -24,12 +24,12 @@ echo To connect to this session copy-n-paste the following into a terminal:
 tmate -S /tmp/tmate.sock display -p '#{tmate_ssh}'
 
 # Wait for connection to close or timeout in 15 min
-timeout=$((2*60))
+timeout=$((15*60))
 while [ -S /tmp/tmate.sock ]; do
   sleep 1
   timeout=$(($timeout-1))
 
-  if [ ! -f /tmp/keepalive ] ; then
+  if [ ! -f /tmp/keepalive ]; then
     if (( timeout < 0 )); then
       echo Waiting on tmate connection timed out!
       exit 1