Update slice append algorithm

Update slice append algorithm according to growslice1.
Merge pull request #4 from NanXiao/patch-2

Update slice append algorithm
Merge pull request #5 from NanXiao/master

Fix typos in 0.2.3.md.
Merge pull request #6 from NanXiao/master

Modify the link of "map的实现"
Update 06.2.md
Merge pull request #7 from hustchensi/patch-1

Update 06.2.md
Merge pull request #2 from tiancaiamao/master

Merge pull requests