v0.3.6

• [Improvement] Add zsh completion at _contrib/completion/zsh (PR #267 @mrymtsk)
• [Improvement] Introduce new subcmd edit (PR #278 @hupfdule, issue #230 @AvianY)
• [Improvement] Place plugconf comments outside of functions (PR #275 @hupfdule)
• [Fix] Don't clone submodules recursively again (issue #260 @ishitaku5522)
• [Fix] Fix documentation bugs (PR #271 @hupfdule)
• [Fix] Fix lots of plugconf generation bugs (PR #276 @hupfdule, PR #266 @sago35, PR #265 @mrymtsk)