* missing 'test2' index example (#39055)
If I got the idea of aliases properly, I think that the index "test2" should have
a reference in the example above of the following sentence:
" ... we associate the alias `alias1` to both `test` and `test2` ... "
* add PUT test2
* Update aliases.asciidoc
swap which is write/read
Co-authored-by: Guilherme Ferreira <guilhermeaferreira_t@yahoo.com.br>