fix grammar in build system documentation

Author: samuelpilz

docs/Build.md

@@ -13,7 +13,7 @@ The design of the build system has the following main goals:
     - a working installation of `stack`
     - `git`
 * is completely functional right after simple `git clone`
-* one-stop-shop for building everything
+* one-stop-shop for building all executables required for using `hie` in IDEs.
 
 See the project's `README` for detailed information about installing `hie`.
 
@@ -26,11 +26,11 @@ A `shake.yaml` is required for executing the `install.hs` file.
 * It contains the required version of `shake`.
 * In contrast to the other `*.yaml` it does not contain the submodules, which is necessary for `stack` to work even before the submodules have been initialized.
 
-It is necessary to update the `resolver` field of the `shake.yaml` if the .
+It is necessary to update the `resolver` field of the `shake.yaml` if the script should run with a different `GHC`.
 
 #### `install.hs` installs a GHC
 
-Before the code in `install.hs` can be executed, `stack` installs a `GHC`, depending on the `resolver` field in `shake.yaml`. This is a necessary if the `install.hs` should be completely functional right after a fresh `git clone` without further configuration.
+Before the code in `install.hs` can be executed, `stack` installs a `GHC`, depending on the `resolver` field in `shake.yaml`. This is necessary if `install.hs` should be completely functional right after a fresh `git clone` without further configuration.
 
 This may lead to an extra `GHC` to be installed by `stack` if not all versions of `haskell-ide-engine` are installed.