impr(userGuide): Improve user guide section

- make an upgrade of bootstrap to the version 3.0
- integrate new navigation sidebar in user guide section
- adjusted style.css

related to CAM-1120
fix(userguide): proofreadand fix cockpit chapter
feat(privacy statement): add privacy statement

Closes: #CAM-1259
fix(user-guide): fix references for cockpit
feat(navigated-docs): add template for docs

Grouped documentation may now be created using the
navigated-docs template.

A file including the navigated-docs template MUST be empty
(except for meta data) and MUST declare a part variable in
its meta data.

Example:

---

layout: 'navigated-docs'
part: 'api-references/rest'

---

The part variable represents the path under which all documents
that should be rendered are to be found.

Each rendered document must include two fields in its meta data:
- title: the title of the document
- category: the category it is displayed under

Example:

---

title: 'Delete Authorization'
category: 'Authorization'

---

Both, categories and files are ordered according to their names,
that is a category named "00-asdf" is rendered before the category
"b" and a document entitled "00-introduction" is rendered before the
document "other-document".

Related to CAM-1120
feat(docs-search): add search to navigatable-docs

Use searchable: true in meta-data to activate.

Related to CAM-1120
chore(api-references/rest): update to new docs style

Related to CAM-1255
fix(api-reference/rest): minor link fix
fix(style/responsive): add word-break to <code>

Add word break to <code> elements to not break user guide on mobile
devices.
chore(user-guide/rest): update to new docs style

related to CAM-1255
chore(api-references/rest): add keywords
fix(nagivated-docs): add debounce on search

Related to CAM-1120
fix(user-guide/pa): Change folder name

related to CAM-1255
Merge branch 'master' of github.com:camunda/docs.camunda.org
feat(docs/single-page): add single page document

New layout 'single-page' may be used to create a single page document
from a group of documentation parts.

The site including the layout must specify the parts via its meta data.

Example:

---

chapters:
    - title: 'REST API'
      part: 'api-references/rest'

    - title: 'User Guide'
      part: 'guides/user-guide'

---

Closes CAM-1265
fix(userguide): fix typos in admin chapter
chore(inst.guide/tomcat): Adjust to new style

related to CAM-1255
Merge branch 'master' of github.com:camunda/docs.camunda.org
updt(installationguide): add hint for cycle

related to CAM-1213
chore(inst.guide): Update to new docs style

related to CAM-1257