Merge branch 'docs/clarify-storage-example-readmes_v6.0' into 'release/v6.0'

docs(storage): clarify example READMEs and when to use each (v6.0)

See merge request espressif/esp-idf!52038

examples/storage/spiffs/README.md

@@ -3,6 +3,8 @@
 
 # SPIFFS example
 
+**Note:** SPIFFS is not recommended for new designs. Use FATFS or LittleFS instead.
+
 (See the README.md file in the upper level 'examples' directory for more information about examples.)
 
 This example demonstrates how to use SPIFFS with ESP32. Example does the following steps:
@@ -17,6 +19,10 @@ This example demonstrates how to use SPIFFS with ESP32. Example does the followi
 
 SPIFFS partition size is set in partitions_example.csv file. See [Partition Tables](https://docs.espressif.com/projects/esp-idf/en/latest/api-guides/partition-tables.html) documentation for more information.
 
+## When to use this example
+
+- You need to work with a legacy SPIFFS image.
+
 ## How to use example
 
 ### Hardware required