Add a few rules about spaces around lambdas and templates to the styl…

…e guide

https://bugs.webkit.org/show_bug.cgi?id=273724

Reviewed by Chris Dumez and Darin Adler.

Fleshes out the rules spaces in and around lambdas and templates.

* Websites/webkit.org/code-style.md:

Canonical link: https://commits.webkit.org/278374@main

Websites/webkit.org/code-style.md

@@ -246,37 +246,78 @@ if(condition)
     doIt();
 ```
 
-[](#spacing-function-paren) Do not place spaces between a function and its parentheses, or between a parenthesis and its content.
+[](#spacing-function-paren-prior) Do not place spaces between the name, angle brackets and parentheses of a function declaration or invocation.
+
+###### Right:
+
+```cpp
+f();
+void g() { ... }
+h<int>();
+```
+
+###### Wrong:
+
+```cpp
+f ();
+void g () { ... }
+h <int> ();
+```
+
+[](#spacing-function-paren-inside) Do not place spaces between the parenthesis and its parameters, or angle brackets and its parameters of a function declaration or invocation.
 
 ###### Right:
 
 ```cpp
 f(a, b);
+void g(int a) { ... }
+h<int>();
 ```
 
 ###### Wrong:
 
 ```cpp
-f (a, b);
 f( a, b );
+void g( int a ) { ... }
+h< int >();
 ```
 
-[](#spacing-lambda-paren) Do not place spaces between square brackets and parentheses of a lambda function but do place a space before braces.
+
+[](#spacing-lambda-paren) Do not place spaces between square brackets, angle brackets and parentheses of a lambda function but do place a space before braces.
 
 ###### Right:
 
 ```cpp
 [](int x) { return x; }
 [this] { return m_member; }
+[=]<typename T> { return T(); }
+[&]<typename X>(X parameter) { return parameter; }
 ```
 
 ###### Wrong:
 
 ```cpp
 [] (int x) { return x; }
 [this]{ return m_member; }
+[=] <typename T> { return T(); }
+[&]<typename X> (X parameter) { return parameter; }
 ```
 
+[](#spacing-template) Do not place spaces between the identifier `template` and its angle brackets.
+
+###### Right:
+
+```cpp
+template<typename T> T foo();
+template<typename U> struct Bar { };
+```
+
+###### Wrong:
+
+```cpp
+template <typename T> T foo();
+template <typename U> struct Bar { };
+
 [](#spacing-braced-init) When initializing an object, place a space before the leading brace as well as between the braces and their content.
 
 ###### Right: