build: switch to C++17

Change-Id: Ie68020a04b7e20b74778b6d0370544ded55c5e26
diff --git a/README.md b/README.md
index b4ce805..910d3f2 100644
--- a/README.md
+++ b/README.md
@@ -1,8 +1,8 @@
-# NFD - Named Data Networking Forwarding Daemon
+# NFD: Named Data Networking Forwarding Daemon
 
 [![CI](https://github.com/named-data/NFD/actions/workflows/ci.yml/badge.svg)](https://github.com/named-data/NFD/actions/workflows/ci.yml)
 [![Docs](https://github.com/named-data/NFD/actions/workflows/docs.yml/badge.svg)](https://github.com/named-data/NFD/actions/workflows/docs.yml)
-![Language](https://img.shields.io/badge/C%2B%2B-14-blue)
+![Language](https://img.shields.io/badge/C%2B%2B-17-blue)
 ![Latest version](https://img.shields.io/github/v/tag/named-data/NFD?label=Latest%20version)
 
 ## Overview