add basic documentation

Readme.md

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+# Binary Database
+
+This is a complete database library made for (Principal of Programming course in University of Shiraz)
+
+## How to use it
+* first create a `Context` object
+* open/create database
+* execute commands with `ctx.exec` to control your data
+* read result of each command at `context.res()` and access to result data on `context.rows()`
+* at last its better to `close` the context, also `clean` context after you're done with its result
+
+## Commands
+1.  `Select(<TableName>, <cols>, <query>)`  OR `Select(<TableName>, <query>, <cols>)` 
+    * select some `DataRow`s from table and read their requested columns that matched in requested Query
+    * you can 
+    * `<TableName>` name of target table bare or wrapped in `"` or `'` or ` (**str-format**)
+    * `<cols>` list of column names styled like above and wrapped in `[ ... ]` to load these columns on each result rows, if not provided: all columns of table will be loaded, if you just want `Row` without their data, just pass an empty list (`[]`)
+    * `<query>` if provided, limits the resulting rows to match the required *Query*
+2.  Comparators Commands: `<cmp>(col, data)`
+    * use bellow functions in `<cmp>` to preform compare Queries
+    * `EQ` as equals, `NEQ` and `NE` as not-equals
+    * `GT` as greater-than, `GE` as greater-than-or-equals
+    * `LT` as less-than, `LE` as less-than-or-equals
+    * `NGT` is `LE` , `NGE` is `LT` , `NLT` is `GE` , `NLE` is `GT`
+    * `In( <col>, <list> )` check value in `<list>` (**lst-format** required)
+3.  Logical Commands:    
+    * `NOT( <query> )` inverse the result returned by query inside
+    * `AND( <q1> , <q2> , ... )` join all query results and return results presented on all queries
+    * `OR( <q1> , <q2> , ... )` merge all query results and return results presented at least on one query
+4.  Table Commands:
+    * `CreateTable( <name>, {<col:type>, ...} )`
+      * create a table named `<name>` with columns with requested type. columns must send in **set-format** `{ ... }` each follows `<col>:<typ>` format.
+    * `DeleteTable( <name> )` Delete table `<name>` from database
+5.  Data Commands:
+    - `Insert( <table>, { <set1> }, { <set2> }, ...)`
+        - insert data into `<table>` each data represented by its `<set>` argument (**set-format** is required).
+        - each `<set>` contains set of `<col>=<val>` to assign data to each data cell
+        - `<val>` type must match `<col>` type
+    - `Update( <table>, { <set> }, <query>)`
+        - update all rows matched in `<query>` with `<set>` parameter
+        - every parameter matches exactly like other functions described above
+    - `Remove( <table>, <query> )`
+        - Remove all rows in `table` matches in `query`
+
+## Data Type
+There is 4 dataType implemented in this Database:
+1. `Byte` or`Char` and their arrays `Byte[fixed]`, `Char[fixed]`
+2. `Int` and `Int[fixed]` hold any Integers
+3. `Real` and `Real[fixed]` holds all Double/Float numbers
+4. `Text` variable size string without any restrictions
+5. In later versions other types than Text, may able to have Variable-Size array
+
+## VarArgs
+You can call `exec` to run requested actions, also you can pass list of `varargs` to fill in the gaps.
+* VarArgs Gap Style `${<index>:<typ>}`:
+  * `<index>` is optional and if its not provided every gap gets its own index start from 1 and continues.
+  * `<typ>` follows like any DataType parameter rules mentioned above.
+
+## Formats
+1. String Format: `" ... "`, `' ... '`
+2. List Format: `[ ..., ... ]`
+3. Set Format: `[ ..., ... ]`
+4. Function Format: `<func>( ..., ... )`
+4. Parenthesis Format: `( ... )`
+4. VarArgs Format: `${<index>:<typ>}`
+
+## Example
+```
+CREATETABLE(students, id:int, name:text, grade:real, year:byte)
+InserT(students, {id=1}, {id=2}, {id=3})
+uPDATE(students, {id=10}, eq(id, 2))
+select(students,[year])
+SELECT(students,eq(year,255)
+Select(students,and( neq(year,94) , neq(id,1374) ))
+
+```