Add lsp signature help (#1755)

* Add lsp signature help

* Do not move signature help popup on multiple triggers

* Highlight current parameter in signature help

* Auto close signature help

* Position signature help above to not block completion

* Update signature help on backspace/insert mode delete

* Add lsp.auto-signature-help config option

* Add serde default annotation for LspConfig

* Show LSP inactive message only if signature help is invoked manually

* Do not assume valid signature help response from LSP

Malformed LSP responses are common, and these should not crash the
editor.

* Check signature help capability before sending request

* Reuse Open enum for PositionBias in popup

* Close signature popup and exit insert mode on escape

* Add config to control signature help docs display

* Use new Margin api in signature help

* Invoke signature help on changing to insert mode

1 files changed, 1 insertions, 1 deletions

diff --git a/helix-term/src/ui/markdown.rs b/helix-term/src/ui/markdown.rs
index a5c78c41..c53b3b66 100644
--- a/helix-term/src/ui/markdown.rs
+++ b/helix-term/src/ui/markdown.rs
@@ -144,7 +144,7 @@ impl Markdown {
         }
     }
 
-    fn parse(&self, theme: Option<&Theme>) -> tui::text::Text<'_> {
+    pub fn parse(&self, theme: Option<&Theme>) -> tui::text::Text<'_> {
         fn push_line<'a>(spans: &mut Vec<Span<'a>>, lines: &mut Vec<Spans<'a>>) {
             let spans = std::mem::take(spans);
             if !spans.is_empty() {