add documents.

Author: suketa

ext/duckdb/instance_cache.c

@@ -47,6 +47,7 @@ static VALUE duckdb_instance_cache_initialize(VALUE self) {
     return self;
 }
 
+/* :nodoc: */
 static VALUE duckdb_instance_cache_get_or_create(int argc, VALUE *argv, VALUE self) {
     VALUE vpath = Qnil;
     VALUE vconfig = Qnil;

lib/duckdb/instance_cache.rb

@@ -11,6 +11,12 @@ module DuckDB
   #   db1 = cache.get(path: 'db.duckdb')
   #   db2 = cache.get(path: 'db.duckdb')
   class InstanceCache
+    # :call-seq:
+    #   instance_cache.get(path:, config:) -> self
+    #
+    # Returns a DuckDB::Database object for the given path and config.
+    #   db1 = cache.get(path: 'db.duckdb')
+    #   db2 = cache.get(path: 'db.duckdb')
     def get(path: nil, config: nil)
       get_or_create(path, config)
     end