fix typo

Co-authored-by: Michael Davis <mcarsondavis@gmail.com>

helix-lsp/src/snippet.rs

@@ -337,8 +337,8 @@ mod parser {
                 digit(),
                 ":",
                 // according to the grammar there is just a single anything here.
-                // However in the procese it is explained that placeholders can be nested
+                // However in the prose it is explained that placeholders can be nested.
-                // the example there contains both a placeholder text and a nested placeholder
+                // The example there contains both a placeholder text and a nested placeholder
                 // which indicates a list. Looking at the VSCode sourcecode, the placeholder
                 // is indeed parsed as zero_or_more so the grammar is simply incorrect here
                 zero_or_more(anything(TEXT_ESCAPE_CHARS)),