Document entity filtering and publish mode settings

[legrego]

Updates to the README:

• Add Table of Contents
• Consolidate usage examples under a single header
• Add documentation for entity inclusion/exclusion & publish mode settings

[github-actions]

Coverage Report

File	Stmts	Miss	Cover	Missing
__init__.py	0	0	100%
elasticsearch
__init__.py	90	2	97%	208–209
config_flow.py	250	28	88%	83, 122, 230, 300, 323, 337, 378–381, 383–384, 386, 388–390, 392–393, 407–408, 412, 452, 458, 498, 573, 582, 616–617
const.py	30	0	100%
entity_details.py	33	0	100%
errors.py	28	3	89%	51, 60, 67
es_doc_creator.py	178	0	100%
es_doc_publisher.py	232	15	93%	97, 213–214, 230–231, 320, 410–411, 413–414, 416–420
es_gateway.py	100	20	80%	82–83, 98, 102, 118–120, 122, 124–125, 127–131, 133–137
es_index_manager.py	121	8	93%	228–229, 246–247, 252–253, 282–283
es_integration.py	37	2	94%	43–44
es_privilege_check.py	55	0	100%
es_serializer.py	10	0	100%
es_version.py	30	0	100%
logger.py	2	0	100%
system_info.py	17	1	94%	23
utils.py	4	0	100%
TOTAL	1217	79	93%

Tests	Skipped	Failures	Errors	Time
95	0 💤	0 ❌	0 🔥	6.128s ⏱️