feat: Add option to blacklist symbols

Closes #38

lua/symbols-outline/config.lua

@@ -19,6 +19,7 @@ local defaults = {
         code_actions = "a"
     },
     lsp_blacklist = {},
+    symbol_blacklist = {},
     symbols = {
         File = {icon = "", hl = "TSURI"},
         Module = {icon = "", hl = "TSNamespace"},
@@ -77,6 +78,11 @@ local function has_value(tab, val)
     return false
 end
 
+function M.is_symbol_blacklisted(kind)
+    if kind == nil then return false end
+    return has_value(M.options.symbol_blacklist, kind)
+end
+
 function M.is_client_blacklisted(client_id)
     local client = vim.lsp.get_client_by_id(client_id)
     return has_value(M.options.lsp_blacklist, client.name)