Update README.md

Corrected the grammar of the document.

README.md

@@ -120,9 +120,9 @@ shell with:
 > python x.py build
 ```
 
-Currently building Rust only works with some known versions of Visual Studio. If
+Currently, building Rust only works with some known versions of Visual Studio. If
 you have a more recent version installed the build system doesn't understand
-then you may need to force rustbuild to use an older version. This can be done
+then you may need to force rust build to use an older version. This can be done
 by manually calling the appropriate vcvars file before running the bootstrap.
 
 ```
@@ -134,7 +134,7 @@ python x.py build
 [specifying-an-abi]: #specifying-an-abi
 
 Each specific ABI can also be used from either environment (for example, using
-the GNU ABI in powershell) by using an explicit build triple. The available
+the GNU ABI in PowerShell) by using an explicit build triple. The available
 Windows build triples are:
 - GNU ABI (using GCC)
     - `i686-pc-windows-gnu`
@@ -159,7 +159,7 @@ $ ./configure
 $ make && sudo make install
 ```
 
-When using the configure script, the generated `config.mk` file may override the
+When using the configure script, the generated `config.mk` the file may override the
 `config.toml` file. To go back to the `config.toml` file, delete the generated
 `config.mk` file.
 
@@ -180,9 +180,9 @@ the ABI used. I.e., if the ABI was `x86_64-pc-windows-msvc`, the directory will
 [notes]: #notes
 
 Since the Rust compiler is written in Rust, it must be built by a
-precompiled "snapshot" version of itself (made in an earlier state of
+precompiled "snapshot" version of itself (made in an earlier stage of
 development). As such, source builds require a connection to the Internet, to
-fetch snapshots, and an OS that can execute the available snapshot binaries.
+fetch snapshots and an OS that can execute the available snapshot binaries.
 
 Snapshot binaries are currently built and tested on several platforms: