ci: restrict token permissions and add badges to README.md

Change-Id: Ia7e254eefb6658aa5110a7fea5a6847cb257a84b

.github/workflows/ci.yml

@@ -1,9 +1,16 @@
 name: CI
 on:
   push:
-  pull_request:
+    paths-ignore:
+      - 'docs/**'
+      - '*.md'
+      - '.mailmap'
+      - '.travis.yml'
   workflow_dispatch:
 
+permissions:
+  contents: read
+
 jobs:
   linux:
     name: ${{ matrix.compiler }} on ${{ matrix.os }}

.github/workflows/docs.yml

@@ -1,9 +1,14 @@
 name: Docs
 on:
   push:
-  pull_request:
+    paths-ignore:
+      - '.mailmap'
+      - '.travis.yml'
   workflow_dispatch:
 
+permissions:
+  contents: read
+
 jobs:
   build:
     strategy:

README.md

@@ -1,8 +1,9 @@
 # NFD - Named Data Networking Forwarding Daemon
 
-![Language](https://img.shields.io/badge/C%2B%2B-14-blue.svg)
-[![Build Status](https://travis-ci.org/named-data/NFD.svg?branch=master)](https://travis-ci.org/named-data/NFD)
-![Latest Version](https://img.shields.io/github/tag/named-data/NFD.svg?color=darkkhaki&label=latest%20version)
+[![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)
+![Latest version](https://img.shields.io/github/v/tag/named-data/NFD?label=Latest%20version)
 
 ## Overview