fix(license): keep LICENSE as verbatim MIT text

GitHub's licensee could not match the file to the MIT template because a scope
note and a horizontal rule were appended after the MIT text, so the repository
was detected as NOASSERTION / Other instead of MIT.

The scope note is already stated at the top of THIRD_PARTY_NOTICES.md, where it
belongs, so the appended copy is removed. LICENSE is now the unmodified MIT
template with only the copyright holder filled in.

LICENSE

@@ -19,10 +19,3 @@ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
-
----
-
-This MIT license covers the original source code and documentation authored
-for html-explainer. It does NOT cover third-party components or the derived
-style specification text, which remain under their own terms. See
-THIRD_PARTY_NOTICES.md for the complete list.