v1.6.2: Add stock order management APIs, update git URLs after migration

What's Changed

• fix: align Gate quickstart with SDK TestNet and settle params by @JJ-Cro in #137
• fix: git url after siebly repo migration by @JJ-Cro in #139
• chore(): README.md template sections by @tiagosiebler in #141
• feat(v1.6.2): add stock API support by @JJ-Cro in #142

Full Changelog: v1.6.1...v1.6.2