Added gitignore templates

ignore/Packer.gitignore

@@ -0,0 +1,16 @@
+# Cache objects
+packer_cache/
+
+# Crash log
+crash.log
+
+# https://www.packer.io/guides/hcl/variables
+# Exclude all .pkrvars.hcl files, which are likely to contain sensitive data,
+# such as password, private keys, and other secrets. These should not be part of
+# version control as they are data points which are potentially sensitive and
+# subject to change depending on the environment.
+#
+*.pkrvars.hcl
+
+# For built boxes
+*.box