admin-guide/basic: align and something fix

From now, I decide to start writing basic document

Signed-off-by: Dunrong Huang <riegamaths@gmail.com>
admin-guide/basic: finish architecture introduction

Signed-off-by: Dunrong Huang <riegamaths@gmail.com>
admin-guide/basic: finish system component

Signed-off-by: Dunrong Huang <riegamaths@gmail.com>
admin-guide/basic: finish resources

Signed-off-by: Dunrong Huang <riegamaths@gmail.com>