meta: cement "Jujutsu" (呪術) as the project name

Many users over the ages have asked about the name of the project, what it
means, and how to refer to it. And occasionally we've talked about changing
the name or getting rid of it, etc.

Recently, there was also confusion about the Japanese interpretation of the name
itself, which can mean either 柔術 (martial arts) or 呪術 (magic, sorcery), each
pronounced differently depending on the exact spelling that English speakers
choose. We've never clarified this or thought about it.

Instead, let's embrace it. I've seen users tend to come away thinking or saying
things like "jj is magic". As a result, the official name in Japanese is now
unambiguously 呪術.

This also adds an FAQ section about the history of the name, the interpretation
of the Japanese word itself, and how to properly refer to it in technical
writing.

Signed-off-by: Austin Seipp <[email protected]>

README.md

@@ -21,12 +21,12 @@
 
 ## Introduction
 
-Jujutsu is a powerful [version control system](https://en.wikipedia.org/wiki/Version_control)
-for software projects. You use it to get a copy of your code, track changes
-to the code, and finally publish those changes for others to see and use.
-It is designed from the ground up to be easy to use—whether you're new or
-experienced, working on brand new projects alone, or large scale software
-projects with large histories and teams.
+Jujutsu (呪術 _Jujutsu_) is a powerful [version control
+system](https://en.wikipedia.org/wiki/Version_control) for software projects.
+You use it to get a copy of your code, track changes to the code, and finally
+publish those changes for others to see and use. It is designed from the ground
+up to be easy to use—whether you're new or experienced, working on brand new
+projects alone, or large scale software projects with large histories and teams.
 
 Jujutsu is unlike most other systems, because internally it abstracts the user
 interface and version control algorithms from the *storage systems* used to
@@ -118,9 +118,8 @@ And it adds several innovative, useful features of its own:
 [undo-history]: https://en.wikipedia.org/wiki/Undo#History
 [conc-safety]: https://martinvonz.github.io/jj/latest/technical/concurrency/
 
-The command-line tool is called `jj` for now because it's easy to type and easy
-to replace (rare in English). The project is called "Jujutsu" because it matches
-"jj".
+The command-line tool is known as `jj`, making it easy to type and easy to
+remember (rare in English).
 
 Jujutsu is relatively young, with lots of work to still be done. If you have any
 questions, or want to talk about future plans, please join us on Discord

docs/FAQ.md

@@ -1,5 +1,7 @@
 # Frequently asked questions
 
+## General Technical Questions
+
 ### Why does my branch not move to the new commit after `jj new/commit`?
 
 If you're familiar with Git, you might expect the current branch to move forward
@@ -179,6 +181,57 @@ directory.
 
 We hope to integrate with Gerrit natively in the future.
 
+## Other Questions
+
+### What's does the name _Jujutsu_ mean, and where does it come from?
+
+When Martin von Zweigbergk originally started the project, it was named called
+"[Jujube](https://en.wikipedia.org/wiki/Jujube)" after a type of fruit. This
+name is what actually gave rise to the lovable and short name `jj` for the
+command line tool. Later on, the the project was renamed to _Jujutsu_ — in
+part because it meant we could keep the command name `jj`.
+
+Jujutsu is a Japanese word that has two distinct interpretations in English,
+each with their own kanji and romanized form:
+
+- 柔術 _Jūjutsu_ — a family of Japanese martial arts, commonly spelled as
+  "**jujitsu**" or "**jiu-jitsu**" in the West. Thankfully, we checked the
+  spelling first.
+
+- 呪術 _Jujutsu_ — roughly meaning "magic" or "sorcery".
+
+However, the basic english word "jujutsu" on its own is somewhat ambiguous to
+native Japanese speakers, because most English words don't use the long vowel
+form "ū", making it unclear what the intended meaning might be when an English
+speaker writes it.
+
+For some time, we left the interpretation ambiguous.
+
+However, we have officially chosen **second** interpretation as the official
+name of the tool, 呪術 _Jujutsu_ as in "sorcery". Many of our users have said
+that as a version control system, Jujutsu simply feels like magic to them, so we
+think this is a fitting interpretation.
+
+The name "Jujutsu" is also known by many of our users through the popular manga
+and anime series _Jujutsu Kaisen_ (呪術廻戦). We didn't choose the name because
+of the series, but we're happy so many people enjoy the connection.
+
+### What's the proper way to refer to the project and tool?
+
+If you are writing a technical document, blog, article, forum post, social media
+endorsement, then the proper name of the project is Jujutsu (呪術 _Jujutsu_) and
+should be referred to as such in the text. Use it like any other proper noun.
+You don't _need_ to specify the kanji and romanized form, though it would be
+courteous to your Japanese-native readers to do so for the reasons explained
+above.
+
+In contrast, the name `jj` only refers to the command line interface of the
+tool, or generally the codebase of the tool itself. When writing about the
+command line interface, please refer to it as `jj` with the proper typographic
+code formatting, etc. (Occasionally though, the developers and contributors
+themselves may refer to the project as `jj` in casual conversations around the
+watercooler.)
+
 [branches_conflicts]: branches.md#conflicts
 
 [change ID]: glossary.md#change-id