Add infomration about MOD-YEAR and MOD-YEAR-RANGE values

Signed-off-by: denis-tingaikin <[email protected]>

Author: denis-tingaikin

README.md

@@ -38,6 +38,8 @@ values:
 
 ## Bult-in values
 
+- **MOD-YEAR** - Returns the year when the file was modified.
+- **MOD-YEAR-RANGE** - Returns a year-range where the range starts from the  year when the file was modified.
 - **YEAR** - Expects current year. Example header value: `2020`.  Example of template using: `{{YEAR}}` or `{{year}}`.
 - **YEAR-RANGE** - Expects any valid year interval or current year. Example header value: `2020` or `2000-2020`. Example of template using: `{{year-range}}` or `{{YEAR-RANGE}}`.