Fix spectre (#520)

* Correctly require Spectre plugin.

Configure backslash as key for interacting with spectre's results.

* Refactor + add Spectre mapping

Map all keys using the mapping variables.
Explicitly specify virtual mappings.

* Remove already prepended character from mapping keys

Co-authored-by: Christian Chiarulli <chris.machine@pm.me>

lua/lv-spectre/init.lua

@@ -0,0 +1,51 @@
+require('spectre').setup({
+ mapping={
+    ['toggle_line'] = {
+        map = "dd",
+        cmd = "<cmd>lua require('spectre').toggle_line()<CR>",
+        desc = "toggle current item"
+    },
+    ['enter_file'] = {
+        map = "<cr>",
+        cmd = "<cmd>lua require('spectre.actions').select_entry()<CR>",
+        desc = "goto current file"
+    },
+    ['send_to_qf'] = {
+        map = "<Blash>q",
+        cmd = "<cmd>lua require('spectre.actions').send_to_qf()<CR>",
+        desc = "send all item to quickfix"
+    },
+    ['replace_cmd'] = {
+        map = "<Bslash>c",
+        cmd = "<cmd>lua require('spectre.actions').replace_cmd()<CR>",
+        desc = "input replace vim command"
+    },
+    ['show_option_menu'] = {
+        map = "<Bslash>o",
+        cmd = "<cmd>lua require('spectre').show_options()<CR>",
+        desc = "show option"
+    },
+    ['run_replace'] = {
+        map = "<Bslash>R",
+        cmd = "<cmd>lua require('spectre.actions').run_replace()<CR>",
+        desc = "replace all"
+    },
+    ['change_view_mode'] = {
+        map = "<Bslash>v",
+        cmd = "<cmd>lua require('spectre').change_view()<CR>",
+        desc = "change result view mode"
+    },
+    ['toggle_ignore_case'] = {
+      map = "ti",
+      cmd = "<cmd>lua require('spectre').change_options('ignore-case')<CR>",
+      desc = "toggle ignore case"
+    },
+    ['toggle_ignore_hidden'] = {
+      map = "th",
+      cmd = "<cmd>lua require('spectre').change_options('hidden')<CR>",
+      desc = "toggle search hidden"
+    },
+    -- you can put your mapping here it only use normal mode
+  }
+})
+