Update README.md with the new program features

README.md

@@ -51,14 +51,56 @@ Then, just type the path to the file:
 
 By default, the program will rename all files in the current directory with the default convention (kebab-case).
 
+### Specifying a different naming convention
+
 You can specify a different naming convention with the first argument you pass to the program e.g.:
 
 ```bash
 ./stdrename snake_case
 ```
 
-You can also specify another folder to parse with a second argument e.g.:
+### Specifying a different folder to parse
+
+You can also specify a different folder to parse with a second argument e.g.:
 
 ```bash
 ./stdrename camelCase ~/Pictures
 ```
+
+### Renaming files in subfolders as well
+
+To rename recursively, use the flag `-r` as the third argument e.g.:
+
+```bash
+./stdrename kebab-case ./new-dir/ -r
+```
+
+### Ignoring files and subdirectories
+
+Finally, you may add a .ignore file with patterns to ignore in the file's directory and its subdirectories.
+
+This file may use any of the glob patterns that can be used in a `.gitignore` file. It is functionally the same, just with a different name e.g.:
+
+Adding the following line in a new .ignore file in the same directory as stdrename will ignore all files with the extension `.py` and all files in the subdirectory `./target/`.
+
+```ignore
+# ./.ignore
+# ignore all files ending with .py
+# ignore all files in /target and its subdirectories
+
+*.py
+/target
+```
+
+You may even add a second .ignore file in a subdirectory e.g.:
+
+```ignore
+# ./subdir1/.ignore
+# match .py files despite previous instructions
+# ignore .txt files in this directory and all subdirectories
+
+!*.py
+*.txt
+```
+
+All files in that directory and all sub directories will then reinclude .py files and ignore .txt files.