feat: [WIP] fetch crate versions and deps using sparse registry index

Author: saecki

doc/crates.txt

@@ -90,7 +90,6 @@ For more information about individual config options see |crates-config|.
         max_parallel_requests = 80,
         open_programs = { "xdg-open", "open" },
         expand_crate_moves_cursor = true,
-        disable_invalid_feature_diagnostic = false,
         enable_update_available_warning = true,
         on_attach = function(bufnr) end,
         text = {
@@ -637,14 +636,6 @@ expand_crate_moves_cursor            *crates-config-expand_crate_moves_cursor*
     Whether to move the cursor on |crates.expand_plain_crate_to_inline_table()|.
 
 
-                            *crates-config-disable_invalid_feature_diagnostic*
-disable_invalid_feature_diagnostic
-    Type: `boolean`, Default: `false`
-
-    This is a temporary solution for:
-    https://github.com/Saecki/crates.nvim/issues/14
-
-
                                *crates-config-enable_update_available_warning*
 enable_update_available_warning
     Type: `boolean`, Default: `true`

docgen/wiki/Documentation-unstable.md

@@ -172,7 +172,6 @@ require("crates").setup {
     max_parallel_requests = 80,
     open_programs = { "xdg-open", "open" },
     expand_crate_moves_cursor = true,
-    disable_invalid_feature_diagnostic = false,
     enable_update_available_warning = true,
     on_attach = function(bufnr) end,
     text = {