add clarifications into README.md

Signed-off-by: Denis Tingajkin <denis.tingajkin@xored.com>

README.md

@@ -13,21 +13,28 @@ go get github.com/denis-tingajkin/go-header/cmd/go-header
 
 ## Configuration
 
-To configuring `go-header.yml` linter you simply need to fill the next structures in YAML format.
-```go
-// Configuration represents go-header linter setup parameters
-type Configuration struct {
-	// Values is map of values. Supports two types 'const` and `regexp`. Values can be used recursively.
-	Values       map[string]map[string]string `yaml:"values"'`
-	// Template is template for checking. Uses values.
-	Template     string                       `yaml:"template"`
-	// TemplatePath path to the template file. Useful if need to load the template from a specific file.
-	TemplatePath string                       `yaml:"template-path"`
-}
+To configuring `.go-header.yml` linter you simply need to fill the next fields:
+
+```yaml
+---
+temaplte: # expects header template string.
+tempalte-path: # expects path to file with license header string. 
+values: # expects `const` or `regexp` node with values where values is a map string to string.
+  const:
+    key1: value1 # const value just checks equality. Note `key1` should be used in template string as {{ key1 }} or {{ KEY1 }}.
+  regexp:
+    key2: value2 # regexp value just checks regex match. The value should be a valid regexp pattern. Note `key2` should be used in template string as {{ key2 }} or {{ KEY2 }}.
+```
+
+Where `values` also can be used recursively. Example:
+
+```yaml
+values:
+  const:
+    key1: "value" 
+  regexp:
+    key2: "{{key1}} value1" # Reads as regex pattern "value value1"
 ```
-Where supported two kinds of values: `const` and `regexp`. NOTE: values can be used recursively. 
-Values ​​with type `const` checks on equality.
-Values ​​with type `regexp` checks on the match.
 
 ## Bult-in values
 
@@ -36,7 +43,7 @@ Values ​​with type `regexp` checks on the match.
 
 ## Execution
 
-`go-header` linter expects file path on input. If you want to run `go-header` only on diff files, then you can use this command.
+`go-header` linter expects file paths on input. If you want to run `go-header` only on diff files, then you can use this command:
 
 ```bash
 go-header $(git diff --name-only | grep -E '.*\.go')
@@ -45,33 +52,30 @@ go-header $(git diff --name-only | grep -E '.*\.go')
 ## Setup example
 
 ### Step 1
-Create configuration file  `.go-header.yaml` in the root of project.
+
+Create configuration file  `.go-header.yml` in the root of project.
+
 ```yaml
 ---
 values:
   const:
     MY COMPANY: mycompany.com
-template-path: ./mypath/mytemplate.txt
-```
+template: |
+  {{ MY COMPANY }}
+  SPDX-License-Identifier: Apache-2.0
 
-### Step 2 
-Write the template file. For example for config above `mytemplate.txt` could be
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at:
 
-```text
-{{ MY COMPANY }}
-SPDX-License-Identifier: Apache-2.0
+  	  http://www.apache.org/licenses/LICENSE-2.0
 
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at:
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
 ```
-### Step 3 
-You are ready! Execute `go-header {FILES}` from the root of the project. 
+
+### Step 2 
+You are ready! Execute `go-header ${PATH_TO_FILES}` from the root of the project.