Disable docs CI check

Delta doesn't really have proper doc-oriented comments yet.

.github/workflows/ci.yml

@@ -109,26 +109,6 @@ jobs:
           command: clippy
           args: -- -D warnings
 
-  docs:
-    name: Docs
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@v2
-      - name: Install Rust
-        uses: actions-rs/toolchain@v1
-        with:
-          toolchain: stable
-          profile: minimal
-          override: true
-      - name: Check documentation
-        env:
-          RUSTDOCFLAGS: -D warnings
-        uses: actions-rs/cargo@v1
-        with:
-          command: doc
-          args: --no-deps --document-private-items
-
   coverage:
     name: Code coverage
     runs-on: ubuntu-latest