Added pre-commit and minor update of version in readme

.editorconfig

+# EditorConfig is awesome: http://EditorConfig.org
+# Uses editorconfig to maintain consistent coding styles
+
+# top-most EditorConfig file
+root = true
+
+# Unix-style newlines with a newline ending every file
+[*]
+charset = utf-8
+end_of_line = lf
+indent_size = 2
+indent_style = space
+insert_final_newline = true
+max_line_length = 80
+trim_trailing_whitespace = true
+
+[*.{tf,tfvars}]
+indent_size = 2
+indent_style = space
+
+[*.md]
+max_line_length = 0
+trim_trailing_whitespace = false
+
+[Makefile]
+tab_width = 2
+indent_style = tab
+
+[COMMIT_EDITMSG]
+max_line_length = 0
\ No newline at end of file

.pre-commit-config.yaml

+repos:
+- repo: git://github.com/antonbabenko/pre-commit-terraform
+  sha: v1.4.0
+  hooks:
+    - id: terraform_fmt
+- repo: git://github.com/pre-commit/pre-commit-hooks
+  sha: v1.2.0
+  hooks:
+    - id: check-merge-conflict

README.md

@@ -61,7 +61,7 @@ module "vote_service_sg" {
 
 **Note:** it is not possible to use variable outputs from this module or other modules that contain calculated values when defining the security group resources. This is typically an issue when specifying either `ingress_with_source_security_group_id` or `egress_with_source_security_group_id` parameters and attempting to use the security group id of a resource which has not yet been created. However referencing variables that are already "hard-coded" in the .tf file (i.e. not calculated values dependent on the infrastructure being created) are fine. E.g. the VPC cidr block `"10.10.0.0/16"`. Also using data sources allows the use of external data/variables that are known at plan time and not regarded as calculated. More details [here](https://github.com/terraform-aws-modules/terraform-aws-security-group/issues/16).
 
-##### 2. Security group with pre-defined rules (NOTE: This is not working with any available version of Terraform, but should be possible in 0.11)
+##### 2. Security group with pre-defined rules (NOTE: Terraform should be version 0.11 or newer)
 
 ```hcl
 module "web_server_sg" {