rename completion -> ide_completion

We don't have completion-related PRs in flight, so lets do it

crates/ide_completion/src/config.rs

@@ -0,0 +1,17 @@
+//! Settings for tweaking completion.
+//!
+//! The fun thing here is `SnippetCap` -- this type can only be created in this
+//! module, and we use to statically check that we only produce snippet
+//! completions if we are allowed to.
+
+use ide_db::helpers::{insert_use::InsertUseConfig, SnippetCap};
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct CompletionConfig {
+    pub enable_postfix_completions: bool,
+    pub enable_imports_on_the_fly: bool,
+    pub add_call_parenthesis: bool,
+    pub add_call_argument_snippets: bool,
+    pub snippet_cap: Option<SnippetCap>,
+    pub insert_use: InsertUseConfig,
+}