Fix typos and markdown (#2388)

* Fix typos

* Align properly

* Update core/consensus/slots/src/lib.rs

Co-Authored-By: cmichi <mich@elmueller.net>

* Update core/network/src/test/mod.rs

Co-Authored-By: cmichi <mich@elmueller.net>

* Update core/finality-grandpa/src/communication/mod.rs

Co-Authored-By: cmichi <mich@elmueller.net>

* Update core/consensus/common/src/import_queue.rs

Co-Authored-By: cmichi <mich@elmueller.net>

substrate/core/consensus/common/src/import_queue.rs

@@ -589,7 +589,7 @@ pub fn import_single_block<B: BlockT, V: Verifier<B>>(
 
 	match import_error(import_handle.check_block(hash, parent))? {
 		BlockImportResult::ImportedUnknown { .. } => (),
-		r @ _ => return Ok(r), // Any other successfull result means that the block is already imported.
+		r => return Ok(r), // Any other successful result means that the block is already imported.
 	}
 
 	let (import_block, new_authorities) = verifier.verify(block_origin, header, justification, block.body)

substrate/core/consensus/rhd/src/lib.rs

@@ -613,7 +613,7 @@ impl<B, P, I> BftService<B, P, I>
 			.map_or(true, |x| self.can_build_on_inner(header, x))
 	}
 
-	/// Get a reference to the underyling client.
+	/// Get a reference to the underlying client.
 	pub fn client(&self) -> &I { &*self.client }
 
 	fn can_build_on_inner(&self, header: &B::Header, live: &(B::Header, AgreementHandle)) -> bool {

substrate/core/consensus/slots/src/lib.rs

@@ -41,7 +41,7 @@ use codec::{Encode, Decode};
 
 /// A worker that should be invoked at every new slot.
 pub trait SlotWorker<B: Block> {
-	/// The type fo the future that will be returned when a new slot is
+	/// The type of the future that will be returned when a new slot is
 	/// triggered.
 	type OnSlot: IntoFuture<Item=(), Error=consensus_common::Error>;