Add technical info to 'About' page and remove 'technical specs' page

Closes #1035

See merge request !1225

README: Adapt to new system with Weblate

See merge request !1218

blog post for release 0.15.0.5

See merge request !1253

Downloads: update link for android ARMv7 and v8

See merge request !1252

update signed hashes

See merge request !1251

update hashes for CLI v0.15.0.5

See merge request !1250

downloads: fix GPG key links

See merge request !1247

Triptych-2 preprint

See merge request !1245

roadmap: change structure

See merge request !1231

Refer to binayFate instead of Fluffypony in guides to verify binaries

Closes #1061

See merge request !1242

press-kit: Change links to monerooutreach.org

See merge request !1240

Add "Is Monero a mixer or mixing service?" question and answer to FAQ

See merge request !1237

Update _i18n/en/resources/developer-guides/wallet-rpc.md

See merge request !1224

Co-authored-by: woodser

posts: add v0.15.0.4 release post

See merge request !1239

Downloads: Avoid using word 'Bootstrap' and change header to 'Import Blockchain'

See merge request !1229

blog: add 'urgent' tag

See merge request !1230

Update hashes and version for gui 0.15.0.4 release

See merge request !1238

Update link to monero-python lib, add link to Vigla.biz gateway

See merge request !1233

The structure of the roadmap isn't meant to support more than 6 tabs, so some changes are necessary to show
the roadmap correctly.

- Grouped the first 2 years 2014-215 on a single tab.
- Added headers for each card
- The last tab is now "Future", and doesn't refer to a specific year, but it's meant to show updates that will be
implemented in the future
- Changed default card from 2019 to 2020

Blog: add posts date, author and nicer category visualization

See merge request !1228

head: fix titles for Moneropedia entries

See merge request !1227

Remove _data/lang/template folder

See merge request !1223

Update Roadmap

See merge request !1222

Downloads: subsitute link to Kastelo website with GitHub

Closes #1027

See merge request !1217

Add new entries under 'Recent News': 'Urgent' and 'Community' and remove 'Announcements'

Closes #1025

See merge request !1215