[DOCFIX] Add vi/vim support in Fuse docs
[DOCFIX] Add vi/vim support in Fuse docs

Modify the doc to document it support vi/vim.

Other than vi/vim, other operations which do the append, modify or
override still not work.
Cp when destination file exist will file.
Append to a file will fail.
Sed to replace content in a file will fail.

Vi/Vim may just be sepcial case that it internally do create a new file,
delete old file, rename the new file to old name operation combinations.

pr-link: Alluxio/alluxio#10146
change-id: cid-c702e5dac664d514bf08b4379a3369a2d92193da
EvilMcJerkface/alluxio,Alluxio/alluxio,maobaolong/alluxio,wwjiang007/alluxio,maobaolong/alluxio,wwjiang007/alluxio,maobaolong/alluxio,Alluxio/alluxio,EvilMcJerkface/alluxio,Alluxio/alluxio,wwjiang007/alluxio,Alluxio/alluxio,Alluxio/alluxio,calvinjia/tachyon,bf8086/alluxio,wwjiang007/alluxio,EvilMcJerkface/alluxio,bf8086/alluxio,maobaolong/alluxio,wwjiang007/alluxio,EvilMcJerkface/alluxio,bf8086/alluxio,maobaolong/alluxio,maobaolong/alluxio,EvilMcJerkface/alluxio,Alluxio/alluxio,Alluxio/alluxio,wwjiang007/alluxio,wwjiang007/alluxio,EvilMcJerkface/alluxio,EvilMcJerkface/alluxio,EvilMcJerkface/alluxio,Alluxio/alluxio,bf8086/alluxio,wwjiang007/alluxio,wwjiang007/alluxio,calvinjia/tachyon,bf8086/alluxio,calvinjia/tachyon,calvinjia/tachyon,bf8086/alluxio,maobaolong/alluxio,Alluxio/alluxio,calvinjia/tachyon,maobaolong/alluxio,wwjiang007/alluxio,maobaolong/alluxio,bf8086/alluxio,bf8086/alluxio,Alluxio/alluxio,calvinjia/tachyon,maobaolong/alluxio,calvinjia/tachyon,calvinjia/tachyon