Docs: fix a few typos like lamba -> lambda

docs/cpp2/declarations.md

@@ -48,7 +48,7 @@ We can illustrate this in two directions. First, let's start with a full functio
 f:(x: int = init) = { /*...*/ }     // x is a parameter to the function
 f:(x: int = init) = statement;      // same, { } is implicit
 
-// Omit name => anonymous function (aka 'lamba')
+// Omit name => anonymous function (aka 'lambda')
  :(x: int = init) = { /*...*/ }     // x is a parameter to the function
  :(x: int = init) = statement;      // same, { } is implicit
 

docs/cpp2/functions.md

@@ -451,7 +451,7 @@ Next, `#!cpp -> _ =` (deduced return type) is the default for single-expression
 equals: (a, b) a == b;
 ```
 
-Finally, at expression scope (aka "lamba/temporary") functions/objects aren't named, and the trailing `;` is optional:
+Finally, at expression scope (aka "lambda/temporary") functions/objects aren't named, and the trailing `;` is optional:
 
 ``` cpp title="(not) 'equals': Identical meaning, but without a name as an unnamed function at expression scope"
 :(a, b) a == b

docs/cpp2/objects.md

@@ -79,7 +79,7 @@ f: () = {
     //  ...  no uses of buf here  ...
     buf = some_calculated_value;        // constructs (not assigns) buf
     //  ...
-    std::cout buf[0];                   // ok, a has been initialized
+    std::cout << buf[0];                // ok, a has been initialized
 }
 
 g: () = {

docs/cpp2/types.md

@@ -180,7 +180,7 @@ All other `#!cpp operator=` functions are explicitly written, either by hand or
 
 ### <a id="memberwise-default"></a> Memberwise by default
 
-All copy/move/comparison `#!cpp operator=` functions are memberwise by default in Cpp2. That includes when you write memberwise construction and assignment yourself.
+All copy/move/conversion `#!cpp operator=` functions are memberwise by default in Cpp2. That includes when you write memberwise construction and assignment yourself.
 
 In a hand-written `#!cpp operator=`:
 

include/cpp2util.h

@@ -1309,7 +1309,7 @@ class out {
 
 //-----------------------------------------------------------------------
 //
-//  CPP2_UFCS: Variadic macro generating a variadic lamba, oh my...
+//  CPP2_UFCS: Variadic macro generating a variadic lambda, oh my...
 //
 //-----------------------------------------------------------------------
 //