DOC: Move all docs into en/ subdirectory (#1505)

* DOC: Move all docs into en/ subdirectory

PR #1502 is working on adding a Chinese translation to the docs. In
general, I encouraged this (in #1452) as a path towards getting useful
translated content in the game without requiring a massive
refactor/rearchitecting of everything.

To support this, this takes the first step of moving our docs into an
en/ subdirectory, so that other languages can live alongside. No effort
is made at this time to support or select between alternate languages;
this is a pure-rename refactor.

src/Documentation/doc/en/advanced/sleeves.md

@@ -0,0 +1,85 @@
+# Sleeves
+
+When VitaLife unveiled their Persona Core technology that allowed people to digitize and transfer their consciousness into other vessels, human bodies became nothing more than 'sleeves' for the human consciousness.
+This technology thus became known as "Sleeve technology".
+
+Sleeve technology unlocks two different gameplay features:
+
+- Duplicate Sleeves
+- [Grafting](grafting.md)
+
+Sleeve technology is unlocked in [BitNode-10](bitnodes.md).
+
+## Duplicate Sleeves
+
+Duplicate Sleeves are MK-V Synthoids (synthetic androids) into which your consciousness has been copied.
+In other words, these Synthoids contain a perfect duplicate of your mind.
+
+Duplicate Sleeves are essentially clones which you can use to perform work-type actions, such as working for a [Company](../basic/companies.md) / [Faction](../basic/factions.md) or committing a [Crime](../basic/crimes.md).
+When sleeves perform these tasks, they will earn money, experience, and [Reputation](../basic/reputation.md).
+
+Sleeves are their own individuals, which means they each have their own experience and stats.
+
+When a sleeve earns experience, it earns experience for itself, the player's original consciousness, as well as all of the player's other sleeves.
+
+Duplicate Sleeves are **not** reset when installing [Augmentations](../basic/augmentations.md), but they are reset when switching [BitNodes](bitnodes.md).
+
+## Obtaining Duplicate Sleeves
+
+There are two methods of obtaining Duplicate Sleeves:
+
+- Destroy [BitNode-10](bitnodes.md).
+  Each completion gives you one additional Duplicate Sleeve.
+- Purchase Duplicate Sleeves from The Covenant.
+  This is only available in [BitNode-10](bitnodes.md).
+  Sleeves purchased this way are **permanent** (they persist through [BitNodes](bitnodes.md)).
+  You can purchase up to 5 Duplicate Sleeves from The Covenant.
+
+## Synchronization
+
+Synchronization is a measure of how aligned your consciousness is with that of your Duplicate Sleeves.
+It is a numerical value between `1` and `100`, and it affects how much experience is earned when the sleeve is performing a task.
+
+Synchronization can be increased by assigning sleeves to the `Synchronize` task.
+
+## Sleeve Shock
+
+Sleeve shock is a measure of how much trauma the sleeve has due to being placed in a new body.
+It is a numerical value between `0` and `100`, where `100` indicates full shock and `0` indicates no shock.
+Shock affects the amount of experience earned by the sleeve.
+
+Sleeve shock slowly decreases over time.
+You can further increase the rate at which it decreases by assigning sleeves to the `Shock Recovery` task.
+
+Let `X` be the sleeve's recovery ratio (calculated as `(100 - shock) / 100`), and `Y` be the sleeve's synchronization ratio (calculated as `synchronize / 100`).
+When performing a task would give you `A` experience normally, the sleeve gains `A * X` experience instead.
+
+The player’s original host consciousness earns a fraction of the experience the sleeve gained, namely `A * X * Y`.
+
+Other sleeves also earn the experience. However, their own shock affects this gain.
+Let `Z` be the receiving sleeve's recovery ratio. It earns `A * X * Y * Z` experience.
+
+## Augmentations
+
+You can purchase [Augmentations](../basic/augmentations.md) for your Duplicate Sleeves.
+In order to do this, the sleeve's shock must be at `0`.
+Any [Augmentation](../basic/augmentations.md) that is currently available to you through a faction is also available for your Duplicate Sleeves.
+There are a few [Augmentations](../basic/augmentations.md), such as NeuroFlux Governor and [Bladeburner](bladeburners.md)-specific ones, that cannot be purchased for a Duplicate Sleeve.
+
+When you purchase an [Augmentation](../basic/augmentations.md) for a Duplicate Sleeve, it is instantly installed.
+When this happens, the sleeve's stats are instantly reset back to 0, similar to when you normally install [Augmentations](../basic/augmentations.md).
+
+The cost of purchasing an [Augmentation](../basic/augmentations.md) for a Duplicate Sleeve is **not** affected by how many [Augmentations](../basic/augmentations.md) you have purchased for yourself, and vice versa.
+
+## Memory
+
+Sleeve memory dictates what a sleeve's synchronization will be when it is reset by switching [BitNodes](bitnodes.md).
+For example, if a sleeve has a memory of `10`, then when you switch [BitNodes](bitnodes.md) its synchronization will initially be set to `10`, rather than 1.
+
+Memory can only be increased by purchasing upgrades from The Covenant.
+Just like the ability to purchase additional sleeves, this is only available in [BitNode-10](bitnodes.md).
+
+Memory is a persistent stat, meaning it never gets reset back to `1`.
+The maximum possible value for a sleeve's memory is `100`.
+
+Buying memory has no instant affect on synchronization - memory affects only the starting synchronization upon entering a [BitNode](bitnodes.md).