chore(deps): bump actions/setup-node from v1 to v2.1.2

Bumps [actions/setup-node](https://github.com/actions/setup-node) from v1 to v2.1.2.
- [Release notes](https://github.com/actions/setup-node/releases)
- [Commits](actions/setup-node@v1...c6fd00c)

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/doctoc.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
-      - uses: actions/setup-node@v1
+      - uses: actions/setup-node@v2.1.2
         with:
           node-version: '12.x'
       - name: Install doctoc

.github/workflows/eclint.yml

@@ -7,7 +7,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
-      - uses: actions/setup-node@v1
+      - uses: actions/setup-node@v2.1.2
         with:
           node-version: '12.x'
       - run: npm i -g eclint

.github/workflows/markdown-link-check.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
-      - uses: actions/setup-node@v1
+      - uses: actions/setup-node@v2.1.2
         with:
           node-version: '12.x'
       - name: Install markdown-link-check