Update API Usage Documentation (IBM#1335)

* Fix gateway APIs
Signed-off-by: Madhav Kandukuri <madhav165@gmail.com>

* Update tool APIs
Signed-off-by: Madhav Kandukuri <madhav165@gmail.com>

* Update server APIs
Signed-off-by: Madhav Kandukuri <madhav165@gmail.com>

* Fix server toggle
Signed-off-by: Madhav Kandukuri <madhav165@gmail.com>

* Fix resource APIs
Signed-off-by: Madhav Kandukuri <madhav165@gmail.com>

* Fix prompt APIs
Signed-off-by: Madhav Kandukuri <madhav165@gmail.com>

* Fix tag APIs
Signed-off-by: Madhav Kandukuri <madhav165@gmail.com>

* Fix tag APIs
Signed-off-by: Madhav Kandukuri <madhav165@gmail.com>

* Fix export APIs
Signed-off-by: Madhav Kandukuri <madhav165@gmail.com>

* Fix import APIs
Signed-off-by: Madhav Kandukuri <madhav165@gmail.com>

* Update A2A endpoints
Signed-off-by: Madhav Kandukuri <madhav165@gmail.com>

* Update end to end example
Signed-off-by: Madhav Kandukuri <madhav165@gmail.com>

Author: madhav165