update README.md according to recent CLI changes

README.md

@@ -8,45 +8,74 @@ Zenith substitutes PostgreSQL storage layer and redistributes data across a clus
 ```sh
 git clone --recursive https://github.com/libzenith/zenith.git
 cd zenith
-make
+make -j5
 ```
 
 2. Start pageserver and postgres on top of it (should be called from repo root):
 ```sh
-# Create ~/.zenith with proper paths to binaries and data
+# Create repository in .zenith with proper paths to binaries and data
 # Later that would be responsibility of a package install script
->./target/debug/zenith init
+> ./target/debug/zenith init
+<...>
+new zenith repository was created in .zenith
 
 # start pageserver
-> ./target/debug/zenith pageserver start
-Starting pageserver at '127.0.0.1:64000'
+> ./target/debug/zenith start
+Starting pageserver at '127.0.0.1:64000' in .zenith
+Pageserver started
 
-# create and configure postgres data dir
-> ./target/debug/zenith pg create
-Creating new postgres: path=/Users/user/code/zenith/tmp_check_cli/compute/pg1 port=55432
-Database initialized
+# start postgres on top on the pageserver
+> ./target/debug/zenith pg start main
+Starting postgres node at 'host=127.0.0.1 port=55432 user=stas'
+waiting for server to start.... done
 
-# start it
-> ./target/debug/zenith pg start pg1
-
-# look up status and connection info
+# check list of running postgres instances
 > ./target/debug/zenith pg list
-NODE		ADDRESS				STATUS
-pg1			127.0.0.1:55432		running
+BRANCH	ADDRESS		LSN		STATUS
+main	127.0.0.1:55432	0/1609610	running
 ```
 
 3. Now it is possible to connect to postgres and run some queries:
-```
+```sh
 > psql -p55432 -h 127.0.0.1 postgres
 postgres=# CREATE TABLE t(key int primary key, value text);
 CREATE TABLE
 postgres=# insert into t values(1,1);
 INSERT 0 1
+postgres=# select * from t;
+ key | value
+-----+-------
+   1 | 1
+(1 row)
+```
+
+4. And create branches and run postgres on them:
+```sh
+# create branch named migration_check
+> ./target/debug/zenith branch migration_check main
+Created branch 'migration_check' at 0/1609610
+
+# check branches tree
+> ./target/debug/zenith branch
+ main
+ ┗━ @0/1609610: migration_check
+
+# start postgres on that branch
+> ./target/debug/zenith pg start migration_check
+Starting postgres node at 'host=127.0.0.1 port=55433 user=stas'
+waiting for server to start.... done
+
+# this new postgres instance will have all the data from 'main' postgres,
+# but all modifications would not affect data in original postgres
+> psql -p55433 -h 127.0.0.1 postgres
 postgres=# select * from t;
  key | value 
 -----+-------
    1 | 1
 (1 row)
+
+postgres=# insert into t values(2,2);
+INSERT 0 1
 ```
 
 ## Running tests
@@ -54,7 +83,7 @@ postgres=# select * from t;
 ```sh
 git clone --recursive https://github.com/libzenith/zenith.git
 make # builds also postgres and installs it to ./tmp_install
-cargo test -- --test-threads=1
+pytest
 ```
 
 ## Source tree layout