Remove some categories in favor of single page enties.

website/docs/tools/webWallet/staking/bond.md

website/docs/tools/webWallet/staking/payout.md

website/docs/tools/webWallet/staking/staking.md

website/docs/tools/webWallet/staking/unbond.md

website/docs/tools/webWallet/staking/validate.md

website/docs/xxchain/API Documents/_category_.json

website/docs/xxchain/governance.md

website/docs/xxchain/runtimeUpdate.md

website/static/img/Dropped Text.txt