Introduce versioning in KubeLB docs

[ahmedwaleedmalik]

For KubeLB, we have just segregated the documentation into Community and Enterprise editions. Both of them serve as the "versions" for KubeLB docs. However, with the new release v1.1 upcoming. We'd also like to introduce a secondary filter/selector that'll represent the actual "version" of the product instead of just the "edition".

[ahmedwaleedmalik]

Although not ideal but we can also cover this by having versions as the selector and editions as sub-topics for the docs, as suggested by @serg
Sample: