Revert "Merge pull #793: Dev Docs: New Glossary & JS Search Box"

This reverts commit e3dcf0ce1f, reversing
changes made to c71e9fdf2d.

Once again we had a broken new plugin that Travis CI and local building
didn't catch.

_data/glossary/en/extended-key.yaml

@@ -1,34 +0,0 @@
----
-# This file is licensed under the MIT License (MIT) available on
-# http://opensource.org/licenses/MIT.
-
-required:
-                                           #-------------40 characters-------------#
-    title_max_40_characters_no_formatting: Extended Key, HD Wallet Extended Key
-
-    summary_max_255_characters_no_formatting: >
-        In the context of HD wallets, a public key or private key
-        extended with the chain code to allow them to derive child keys.
-
-    synonyms_shown_in_glossary_capitalize_first_letter:
-        - Extended key
-        - Public extended key
-        - Private extended key
-
-optional:
-    synonyms_and_pluralizations_not_shown_in_glossary:
-        - extended keys
-        - public extended keys
-        - private extended keys
-        - public and private extended key
-        - public and private extended keys
-        - private and public extended key
-        - private and public extended keys
-
-    not_to_be_confused_with_capitalize_first_letter:
-
-    links_html_or_markdown_style_capitalize_first_letter:
-        - "[Extended key](/en/developer-guide#term-extended-key) --- Bitcoin.org Developer Guide"
-        - "[BIP32: hierarchical deterministic wallets](https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki) --- Bitcoin Improvement Proposals"
-
----