fix typos and make comments clearer

Author: Aurélien Richez

src/main/resources/conf/base.conf

@@ -254,11 +254,11 @@ mantis {
       }
 
       health {
-        # If the client does see a change of the best known block number after this duration
-        # the healthcheck will consider it to be stuck and return an error
+        # If the best known block number stays the same for more time than this,
+        # the healthcheck will consider the client to be stuck and return an error
         no-update-duration-threshold = 30.minutes
-        # If the client best known stored block is behind the best known block by more blocks
-        # than this parameter, we consider that it is syncing in the healthcheck
+        # If the difference between the best stored block number and the best known block number
+        # is less than this value, the healthcheck will report that the client is synced.
         syncing-status-threshold = 10
       }
 

src/test/scala/io/iohk/ethereum/jsonrpc/server/http/JsonRpcHttpServerSpec.scala

@@ -47,7 +47,7 @@ class JsonRpcHttpServerSpec extends AnyFlatSpec with Matchers with ScalatestRout
     }
   }
 
-  it should "respond to healthcheck with an error if one healtcheck fails" in new TestSetup {
+  it should "respond to healthcheck with an error if one healthcheck fails" in new TestSetup {
     (mockJsonRpcHealthChecker.healthCheck _)
       .expects()
       .returning(