Minor spelling fixes and tweaks to headers and docs.

Author: eieio

README.md

@@ -15,7 +15,7 @@ libnop has the following goals:
     types, formats, and protocols: perform these tasks naturally within the C++
     language.
   * Avoid additional runtime support requirements for serialization.
-  * Provide contemporary features such as bi-directional binary compatability,
+  * Provide contemporary features such as bidirectional binary compatability,
     data validation, type safety, and type fungibility.
   * Handle intrinsic types, common STL types and containers, and user-defined
     types with a minimum of effort.

docs/getting-started.md

@@ -237,7 +237,7 @@ struct TemplateType {
 // public methods to enforce policy on how the data may be used.
 class Items {
  public:
-  Items = default;
+  Items() = default;
   Items(std::vector<std::string> items) : items_{std::move(items)} {}
   Items(const Items&) = default;
   Items(Items&&) = default;

include/nop/utility/backtrace.h

@@ -31,7 +31,7 @@ namespace nop {
 //
 // Backtrace utility based on the UNIX backtrace API.
 //
-// Provides a simple mechanism to generate a backtrace with sumbol lookup.
+// Provides a simple mechanism to generate a backtrace with symbol lookup.
 //
 
 class Backtrace {