Commit 5e8795eebe has changed the partition table offset, which
has resulted in the ciphertext not matching the one expected in the
example test.
Fix by calculating the ciphertext using espsecure.py.
When the flash encryption is enabled then we do not need to change the partition table.
The partition_example.csv should not have fixed offsets for partitions because we want to move the whole table.
The fixed offsets in the table were cleared.
This MR improves existing flash encryption document to provide simplified steps
Adds two new modes for user: Development & Release
Adds a simple example
Supports encrypted write through make command
