[Improvement] Add lspkind.nvim is a dependency, since it obviously is one.

[cmon1701]

Add lspkind.nvim as a dependency.

Without it, I get the error:

Error executing Lua callback: ...issues-minimal/lazy/lspsaga.nvim/lua/lspsaga/lspkind.lua:1: attempt to index field 'config' (a nil value)                  
stack traceback:                                                                                                                                            
        ...issues-minimal/lazy/lspsaga.nvim/lua/lspsaga/lspkind.lua:1: in main chunk                                                                        
        [C]: in function 'require'                                                                                                                          
        ...minimal/lazy/lspsaga.nvim/lua/lspsaga/symbol/outline.lua:5: in main chunk                                                                        
        [C]: in function 'require'                                                                                                                          
        ...es-minimal/lazy/lspsaga.nvim/lua/lspsaga/symbol/init.lua:222: in function 'outline'                                                              
        ...issues-minimal/lazy/lspsaga.nvim/lua/lspsaga/command.lua:50: in function <...issues-minimal/lazy/lspsaga.nvim/lua/lspsaga/command.lua:49>        
        ...issues-minimal/lazy/lspsaga.nvim/lua/lspsaga/command.lua:80: in function 'load_command'                                                          
        ...nvim-issues-minimal/lazy/lspsaga.nvim/plugin/lspsaga.lua:8: in function <...nvim-issues-minimal/lazy/lspsaga.nvim/plugin/lspsaga.lua:7>