key_value: keep lambda declaration on same line

Fixes #30

src/rules/key_value.rs

@@ -47,6 +47,7 @@ pub fn rule(
         crate::config::Layout::Tall => {
             if let rnix::SyntaxKind::NODE_APPLY
             | rnix::SyntaxKind::NODE_ATTR_SET
+            | rnix::SyntaxKind::NODE_LAMBDA
             | rnix::SyntaxKind::NODE_LIST
             | rnix::SyntaxKind::NODE_PAREN
             | rnix::SyntaxKind::NODE_STRING =

tests/cases/key_value/in

@@ -7,4 +7,8 @@
   f = {a/*b*/=     1/*d*/;};
   h = {a/*b*/=/*c*/1     ;};
   i = {a/*b*/=/*c*/1/*d*/;};
+  j = a:       {    b = 1           ;};
+  k = a:       {    b = 1;     c = 2;};
+  l = a: /*b*/ {    b = 1           ;};
+  m = a: /*b*/ {    b = 1;     c = 2;};
 }

tests/cases/key_value/out

@@ -72,4 +72,22 @@
        */
       ;
   };
+  j = a: { b = 1; };
+  k = a: {
+    b = 1;
+    c = 2;
+  };
+  l = a:
+  /*
+   b
+   */
+  { b = 1; };
+  m = a:
+  /*
+   b
+   */
+  {
+    b = 1;
+    c = 2;
+  };
 }