Update md-to-clip page: (#9978)

- add new examples

pages/common/md-to-clip.md

@@ -12,6 +12,14 @@
 
 `md-to-clip --output-directory {{path/to/directory}} {{path/to/page1.md path/to/page2.md ...}}`
 
+- Convert a tldr-page file to stdout:
+
+`md-to-clip --no-file-save <(echo '{{page-content}}')`
+
+- Convert tldr-pages files while recognizing additional placeholders from a specific config:
+
+`md-to-clip --special-placeholder-config {{path/to/config.yaml}} {{path/to/page1.md path/to/page2.md ...}}`
+
 - Display help:
 
 `md-to-clip --help`